My program is doing everything that it should except that when it runs through t
ID: 3820783 • Letter: M
Question
My program is doing everything that it should except that when it runs through test.showPrimes the second time, it does not print the sexy primes that fall between the user's low and upper boundaries that they specified. I don't understand why. I've tried everything that I can think of. I cannot separate the method into two methods so that I can return values. It has to be done with the one method that sets the boundaries.
-----------------------------------------------
import java.util.Scanner;
public class Sieve {
/**
* This is the main method, it defines variables used throughout the
* program and creates a new scanner for user input.
*
* @return nothing
*/
public static void main (String args[]) {
}//end main
/**
* This method (processSieve) creates an array with prime numbers
*
* @param boolean[] primes, int highnum
* @return nothing
*/
public void processSieve (boolean[] primes, int highnum) {
for (int i=2; i<=highnum; i++) {
primes[i] = true;
}
for (int i=2; i*i<=highnum; i++ ) {
if (primes[i]) {
for (int z =i; i*z<=highnum; z++) {
primes [i*z] = false;
}
}
}
}//end processSieve
/**
* This method (intro) prints information about the Sieve of Eratosthenes to the screen
*
* @return nothing
*/
public void intro () {
System.out.println (" The Sieve of Eratosthenes! The Sieve of Eratosthenes " +
"is an ancient algorithm for finding all prime numbers up " +
"to a specific number from the set of integers. We use this " +
"to find a second mathematical series called Sexy Twins or " +
"Sexy Primes (from the Latin for six) or sets of prime numbers " +
"which are only 6 digits apart like the numbers 7 and 13. You " +
"will need to enter an upper and lower boundary between 1 and " +
"50000. We'll give you the Sexy Primes between them. ");
System.out.print ("Please enter a lower boundary and an upper boundary and I will" +
" print all of the sexy prime pairs between those boundaries. ");
}//end intro
/**
* This method (getBoundaries) sets the low boundary from user input
*
* @param int lowNum, int highNum
* @return nothing
*/
public void getBoundaries (int lowNum, int highNum) {
Scanner in = new Scanner (System.in);
do {
do {
System.out.print ("Please enter the lower boundary (between 1 and 50000): ");
lowNum = in.nextInt();
} while (lowNum<=0 || lowNum>50000);
do {
System.out.print ("Please enter the upper boundary (between 1 and 50000): ");
highNum = in.nextInt();
while (highNum<lowNum) {
System.out.print (" Your upper boundary cannot be smaller than your lower boundary ");
System.out.print ("Please enter the lower boundary (between 1 and 50000): ");
lowNum = in.nextInt();
System.out.print ("Please enter the upper boundary (between 1 and 50000): ");
highNum = in.nextInt();
}
} while (highNum<=0 || highNum >50000);
} while (lowNum == highNum);
}//end getBoundaries
/**
* This method (showPrimes) prints the sexy primes and tallies them
*
* @param boolean[] primes, int lowNum, int highNum
* @return nothing
*/
public void showPrimes (boolean[] primes, int lowNum, int highNum) {
int count = 0;
for (int i=lowNum; i<highNum-6; i++) {
if (primes[i]==true && primes [i+6]==true) {
++count;
System.out.println (i + " and " + (i+6) );
}
}
System.out.println (" There were " + count + " sexy prime pairs displayed between "
+ lowNum + " and " + highNum);
}//end showPrimes
}//end class
-----------------------------------------------
public class SieveTest {
public static void main (String args []) {
final int endNum = 50000;
boolean[] primes = new boolean [endNum +1];
int lowNum = 1;
int highNum = endNum;
Sieve test = new Sieve();
test.processSieve(primes, highNum); //run the Sieve algorithm
test.showPrimes(primes, lowNum, highNum); //show entire set of sexy pairs, 1419 of them
test.intro(); //show the introductory remarks
test.getBoundaries(lowNum, highNum); //get low and high boundary from the user
test.showPrimes(primes, lowNum, highNum); //now shows sexy pairs between lower and upper
}
}
Explanation / Answer
HI, Please find my standard implementation.
Please let me know in case of any issue.
#####################
import java.util.Scanner;
public class Sieve {
private int lowNum;
private int highNum;
public Sieve() {
// default bondary
lowNum = 1;
highNum = 50000;
}
/**
* This method (processSieve) creates an array with prime numbers
*
* @param boolean[] primes, int highnum
* @return nothing
*/
public void processSieve (boolean[] primes, int highnum) {
for (int i=2; i<=highnum; i++) {
primes[i] = true;
}
for (int i=2; i*i<=highnum; i++ ) {
if (primes[i]) {
for (int z =i; i*z<=highnum; z++) {
primes [i*z] = false;
}
}
}
}//end processSieve
/**
* This method (intro) prints information about the Sieve of Eratosthenes to the screen
*
* @return nothing
*/
public void intro () {
System.out.println (" The Sieve of Eratosthenes! The Sieve of Eratosthenes " +
"is an ancient algorithm for finding all prime numbers up " +
"to a specific number from the set of integers. We use this " +
"to find a second mathematical series called Sexy Twins or " +
"Sexy Primes (from the Latin for six) or sets of prime numbers " +
"which are only 6 digits apart like the numbers 7 and 13. You " +
"will need to enter an upper and lower boundary between 1 and " +
"50000. We'll give you the Sexy Primes between them. ");
System.out.print ("Please enter a lower boundary and an upper boundary and I will" +
" print all of the sexy prime pairs between those boundaries. ");
}//end intro
/**
* This method (getBoundaries) sets the low boundary from user input
*
* @param int lowNum, int highNum
* @return nothing
*/
public void getBoundaries () {
Scanner in = new Scanner (System.in);
do {
do {
System.out.print ("Please enter the lower boundary (between 1 and 50000): ");
lowNum = in.nextInt();
} while (lowNum<=0 || lowNum>50000);
do {
System.out.print ("Please enter the upper boundary (between 1 and 50000): ");
highNum = in.nextInt();
while (highNum<lowNum) {
System.out.print (" Your upper boundary cannot be smaller than your lower boundary ");
System.out.print ("Please enter the lower boundary (between 1 and 50000): ");
lowNum = in.nextInt();
System.out.print ("Please enter the upper boundary (between 1 and 50000): ");
highNum = in.nextInt();
}
} while (highNum<=0 || highNum >50000);
} while (lowNum == highNum);
in.close();
}//end getBoundaries
/**
* This method (showPrimes) prints the sexy primes and tallies them
*
* @param boolean[] primes, int lowNum, int highNum
* @return nothing
*/
public void showPrimes (boolean[] primes) {
int count = 0;
for (int i=lowNum; i<highNum-6; i++) {
if (primes[i]==true && primes [i+6]==true) {
++count;
System.out.println (i + " and " + (i+6) );
}
}
System.out.println (" There were " + count + " sexy prime pairs displayed between "
+ lowNum + " and " + highNum);
}//end showPrimes
}//end class
#############################
public class SieveTest {
public static void main (String args []) {
final int endNum = 50000;
boolean[] primes = new boolean [endNum +1];
int lowNum = 1;
int highNum = endNum;
Sieve test = new Sieve();
test.processSieve(primes, highNum); //run the Sieve algorithm
test.showPrimes(primes); //show entire set of sexy pairs, 1419 of them
test.intro(); //show the introductory remarks
test.getBoundaries(); //get low and high boundary from the user
test.showPrimes(primes); //now shows sexy pairs between lower and upper
}
}
/*
Sample run:
5 and 11
7 and 13
11 and 17
13 and 19
17 and 23
23 and 29
31 and 37
37 and 43
41 and 47
47 and 53
53 and 59
61 and 67
67 and 73
73 and 79
83 and 89
97 and 103
101 and 107
103 and 109
107 and 113
131 and 137
151 and 157
157 and 163
167 and 173
173 and 179
191 and 197
193 and 199
223 and 229
227 and 233
233 and 239
251 and 257
257 and 263
263 and 269
271 and 277
277 and 283
307 and 313
311 and 317
331 and 337
347 and 353
353 and 359
367 and 373
373 and 379
383 and 389
433 and 439
443 and 449
457 and 463
461 and 467
503 and 509
541 and 547
557 and 563
563 and 569
571 and 577
587 and 593
593 and 599
601 and 607
607 and 613
613 and 619
641 and 647
647 and 653
653 and 659
677 and 683
727 and 733
733 and 739
751 and 757
821 and 827
823 and 829
853 and 859
857 and 863
877 and 883
881 and 887
941 and 947
947 and 953
971 and 977
977 and 983
991 and 997
1013 and 1019
1033 and 1039
1063 and 1069
1087 and 1093
1091 and 1097
1097 and 1103
1103 and 1109
1117 and 1123
1123 and 1129
1181 and 1187
1187 and 1193
1217 and 1223
1223 and 1229
1231 and 1237
1277 and 1283
1283 and 1289
1291 and 1297
1297 and 1303
1301 and 1307
1321 and 1327
1361 and 1367
1367 and 1373
1423 and 1429
1427 and 1433
1433 and 1439
1447 and 1453
1453 and 1459
1481 and 1487
1483 and 1489
1487 and 1493
1493 and 1499
1543 and 1549
1553 and 1559
1601 and 1607
1607 and 1613
1613 and 1619
1621 and 1627
1657 and 1663
1663 and 1669
1693 and 1699
1741 and 1747
1747 and 1753
1753 and 1759
1777 and 1783
1783 and 1789
1861 and 1867
1867 and 1873
1871 and 1877
1873 and 1879
1901 and 1907
1907 and 1913
1973 and 1979
1987 and 1993
1993 and 1999
1997 and 2003
2011 and 2017
2063 and 2069
2081 and 2087
2083 and 2089
2131 and 2137
2137 and 2143
2207 and 2213
2237 and 2243
2267 and 2273
2281 and 2287
2287 and 2293
2333 and 2339
2341 and 2347
2351 and 2357
2371 and 2377
2377 and 2383
2383 and 2389
2393 and 2399
2411 and 2417
2417 and 2423
2441 and 2447
2467 and 2473
2543 and 2549
2551 and 2557
2657 and 2663
2671 and 2677
2677 and 2683
2683 and 2689
2687 and 2693
2693 and 2699
2707 and 2713
2713 and 2719
2791 and 2797
2797 and 2803
2837 and 2843
2851 and 2857
2897 and 2903
2903 and 2909
2957 and 2963
2963 and 2969
3061 and 3067
3083 and 3089
3163 and 3169
3181 and 3187
3203 and 3209
3251 and 3257
3253 and 3259
3301 and 3307
3307 and 3313
3313 and 3319
3323 and 3329
3407 and 3413
3457 and 3463
3461 and 3467
3463 and 3469
3511 and 3517
3527 and 3533
3533 and 3539
3541 and 3547
3607 and 3613
3617 and 3623
3631 and 3637
3637 and 3643
3671 and 3677
3691 and 3697
3727 and 3733
3733 and 3739
3761 and 3767
3797 and 3803
3847 and 3853
3911 and 3917
3917 and 3923
3923 and 3929
4001 and 4007
4007 and 4013
4013 and 4019
4021 and 4027
4051 and 4057
4073 and 4079
4093 and 4099
4127 and 4133
4133 and 4139
4153 and 4159
4211 and 4217
4253 and 4259
4283 and 4289
4357 and 4363
4391 and 4397
4441 and 4447
4451 and 4457
4457 and 4463
4507 and 4513
4513 and 4519
4517 and 4523
4561 and 4567
4591 and 4597
4597 and 4603
4637 and 4643
4643 and 4649
4651 and 4657
4657 and 4663
4673 and 4679
4723 and 4729
4783 and 4789
4787 and 4793
4793 and 4799
4871 and 4877
4903 and 4909
4931 and 4937
4937 and 4943
4951 and 4957
4967 and 4973
4987 and 4993
4993 and 4999
5003 and 5009
5081 and 5087
5101 and 5107
5107 and 5113
5113 and 5119
5147 and 5153
5227 and 5233
5231 and 5237
5273 and 5279
5297 and 5303
5303 and 5309
5381 and 5387
5387 and 5393
5393 and 5399
5407 and 5413
5413 and 5419
5431 and 5437
5437 and 5443
5443 and 5449
5471 and 5477
5477 and 5483
5501 and 5507
5521 and 5527
5557 and 5563
5563 and 5569
5641 and 5647
5647 and 5653
5651 and 5657
5653 and 5659
5683 and 5689
5711 and 5717
5737 and 5743
5743 and 5749
5801 and 5807
5807 and 5813
5821 and 5827
5843 and 5849
5851 and 5857
5861 and 5867
5897 and 5903
5981 and 5987
6037 and 6043
6047 and 6053
6067 and 6073
6073 and 6079
6197 and 6203
6211 and 6217
6257 and 6263
6263 and 6269
6271 and 6277
6311 and 6317
6317 and 6323
6323 and 6329
6337 and 6343
6353 and 6359
6361 and 6367
6367 and 6373
6373 and 6379
6421 and 6427
6547 and 6553
6563 and 6569
6571 and 6577
6653 and 6659
6673 and 6679
6703 and 6709
6823 and 6829
6827 and 6833
6857 and 6863
6863 and 6869
6911 and 6917
6961 and 6967
6971 and 6977
6977 and 6983
6991 and 6997
7013 and 7019
7103 and 7109
7121 and 7127
7187 and 7193
7207 and 7213
7213 and 7219
7237 and 7243
7247 and 7253
7411 and 7417
7451 and 7457
7481 and 7487
7517 and 7523
7523 and 7529
7541 and 7547
7577 and 7583
7583 and 7589
7643 and 7649
7681 and 7687
7717 and 7723
7753 and 7759
7817 and 7823
7823 and 7829
7867 and 7873
7873 and 7879
7877 and 7883
7901 and 7907
7927 and 7933
8011 and 8017
8053 and 8059
8081 and 8087
8087 and 8093
8111 and 8117
8117 and 8123
8161 and 8167
8231 and 8237
8237 and 8243
8263 and 8269
8287 and 8293
8291 and 8297
8311 and 8317
8363 and 8369
8423 and 8429
8461 and 8467
8521 and 8527
8537 and 8543
8623 and 8629
8641 and 8647
8663 and 8669
8693 and 8699
8707 and 8713
8713 and 8719
8731 and 8737
8741 and 8747
8747 and 8753
8831 and 8837
8861 and 8867
8887 and 8893
8923 and 8929
8963 and 8969
9001 and 9007
9007 and 9013
9043 and 9049
9103 and 9109
9127 and 9133
9151 and 9157
9181 and 9187
9203 and 9209
9221 and 9227
9277 and 9283
9337 and 9343
9343 and 9349
9371 and 9377
9391 and 9397
9397 and 9403
9413 and 9419
9431 and 9437
9433 and 9439
9461 and 9467
9467 and 9473
9473 and 9479
9491 and 9497
9533 and 9539
9613 and 9619
9623 and 9629
9643 and 9649
9733 and 9739
9743 and 9749
9781 and 9787
9811 and 9817
9833 and 9839
9851 and 9857
9901 and 9907
9923 and 9929
9967 and 9973
10061 and 10067
10093 and 10099
10133 and 10139
10163 and 10169
10247 and 10253
10253 and 10259
10267 and 10273
10331 and 10337
10337 and 10343
10427 and 10433
10453 and 10459
10457 and 10463
10601 and 10607
10607 and 10613
10651 and 10657
10657 and 10663
10723 and 10729
10733 and 10739
10831 and 10837
10847 and 10853
10853 and 10859
10861 and 10867
10883 and 10889
10903 and 10909
10973 and 10979
10987 and 10993
11087 and 11093
11113 and 11119
11171 and 11177
11251 and 11257
11273 and 11279
11311 and 11317
11393 and 11399
11437 and 11443
11483 and 11489
11491 and 11497
11497 and 11503
11587 and 11593
11777 and 11783
11783 and 11789
11801 and 11807
11807 and 11813
11821 and 11827
11827 and 11833
11833 and 11839
11897 and 11903
11903 and 11909
11927 and 11933
11933 and 11939
11953 and 11959
11981 and 11987
12037 and 12043
12043 and 12049
12101 and 12107
12107 and 12113
12113 and 12119
12143 and 12149
12157 and 12163
12197 and 12203
12263 and 12269
12323 and 12329
12373 and 12379
12451 and 12457
12473 and 12479
12491 and 12497
12497 and 12503
12511 and 12517
12541 and 12547
12547 and 12553
12577 and 12583
12583 and 12589
12613 and 12619
12641 and 12647
12647 and 12653
12653 and 12659
12697 and 12703
12757 and 12763
12823 and 12829
12893 and 12899
12911 and 12917
12917 and 12923
12953 and 12959
12967 and 12973
12973 and 12979
13001 and 13007
13003 and 13009
13037 and 13043
13043 and 13049
13093 and 13099
13103 and 13109
13121 and 13127
13171 and 13177
13177 and 13183
13291 and 13297
13331 and 13337
13411 and 13417
13451 and 13457
13457 and 13463
13463 and 13469
13591 and 13597
13613 and 13619
13627 and 13633
13681 and 13687
13687 and 13693
13691 and 13697
13723 and 13729
13751 and 13757
13757 and 13763
13873 and 13879
13877 and 13883
13901 and 13907
13907 and 13913
14051 and 14057
14081 and 14087
14143 and 14149
14153 and 14159
14243 and 14249
14321 and 14327
14341 and 14347
14401 and 14407
14431 and 14437
14537 and 14543
14543 and 14549
14551 and 14557
14557 and 14563
14621 and 14627
14627 and 14633
14633 and 14639
14717 and 14723
14731 and 14737
14741 and 14747
14747 and 14753
14753 and 14759
14821 and 14827
14891 and 14897
14923 and 14929
14951 and 14957
15077 and 15083
15101 and 15107
15131 and 15137
15187 and 15193
15193 and 15199
15227 and 15233
15263 and 15269
15271 and 15277
15307 and 15313
15313 and 15319
15377 and 15383
15461 and 15467
15467 and 15473
15601 and 15607
15641 and 15647
15643 and 15649
15661 and 15667
15727 and 15733
15731 and 15737
15733 and 15739
15761 and 15767
15767 and 15773
15791 and 15797
15797 and 15803
15803 and 15809
15817 and 15823
15881 and 15887
15901 and 15907
15907 and 15913
15913 and 15919
16001 and 16007
16057 and 16063
16061 and 16067
16063 and 16069
16067 and 16073
16091 and 16097
16097 and 16103
16183 and 16189
16187 and 16193
16217 and 16223
16223 and 16229
16267 and 16273
16333 and 16339
16363 and 16369
16411 and 16417
16421 and 16427
16427 and 16433
16447 and 16453
16481 and 16487
16487 and 16493
16547 and 16553
16561 and 16567
16567 and 16573
16651 and 16657
16693 and 16699
16741 and 16747
16823 and 16829
16883 and 16889
16921 and 16927
16931 and 16937
16937 and 16943
16981 and 16987
16987 and 16993
17021 and 17027
17027 and 17033
17041 and 17047
17047 and 17053
17093 and 17099
17117 and 17123
17183 and 17189
17203 and 17209
17293 and 17299
17321 and 17327
17327 and 17333
17377 and 17383
17383 and 17389
17387 and 17393
17443 and 17449
17471 and 17477
17477 and 17483
17483 and 17489
17491 and 17497
17573 and 17579
17707 and 17713
17783 and 17789
17903 and 17909
17923 and 17929
17971 and 17977
17981 and 17987
18041 and 18047
18043 and 18049
18121 and 18127
18127 and 18133
18143 and 18149
18211 and 18217
18217 and 18223
18223 and 18229
18251 and 18257
18301 and 18307
18307 and 18313
18427 and 18433
18433 and 18439
18451 and 18457
18517 and 18523
18587 and 18593
18713 and 18719
18743 and 18749
18787 and 18793
18797 and 18803
18911 and 18917
18913 and 18919
18973 and 18979
19031 and 19037
19073 and 19079
19081 and 19087
19157 and 19163
19207 and 19213
19213 and 19219
19231 and 19237
19267 and 19273
19373 and 19379
19381 and 19387
19417 and 19423
19421 and 19427
19423 and 19429
19427 and 19433
19441 and 19447
19457 and 19463
19463 and 19469
19471 and 19477
19477 and 19483
19483 and 19489
19501 and 19507
19553 and 19559
19571 and 19577
19577 and 19583
19597 and 19603
19603 and 19609
19681 and 19687
19753 and 19759
19813 and 19819
19861 and 19867
19913 and 19919
19973 and 19979
19991 and 19997
20023 and 20029
20101 and 20107
20107 and 20113
20117 and 20123
20123 and 20129
20143 and 20149
20177 and 20183
20327 and 20333
20341 and 20347
20347 and 20353
20353 and 20359
20393 and 20399
20477 and 20483
20543 and 20549
20593 and 20599
20743 and 20749
20747 and 20753
20753 and 20759
20873 and 20879
20897 and 20903
21011 and 21017
21013 and 21019
21017 and 21023
21061 and 21067
21101 and 21107
21143 and 21149
21157 and 21163
21163 and 21169
21187 and 21193
21221 and 21227
21277 and 21283
21313 and 21319
21317 and 21323
21341 and 21347
21377 and 21383
21391 and 21397
21401 and 21407
21481 and 21487
21487 and 21493
21493 and 21499
21517 and 21523
21523 and 21529
21557 and 21563
21563 and 21569
21611 and 21617
21751 and 21757
21767 and 21773
21937 and 21943
21991 and 21997
21997 and 22003
22031 and 22037
22067 and 22073
22073 and 22079
22123 and 22129
22147 and 22153
22153 and 22159
22271 and 22277
22273 and 22279
22277 and 22283
22343 and 22349
22391 and 22397
22441 and 22447
22447 and 22453
22543 and 22549
22567 and 22573
22613 and 22619
22637 and 22643
22691 and 22697
22721 and 22727
22777 and 22783
22811 and 22817
22853 and 22859
22871 and 22877
22901 and 22907
22937 and 22943
23011 and 23017
23021 and 23027
23053 and 23059
23057 and 23063
23081 and 23087
23167 and 23173
23197 and 23203
23203 and 23209
23291 and 23297
23321 and 23327
23327 and 23333
23333 and 23339
23531 and 23537
23557 and 23563
23561 and 23567
23593 and 23599
23603 and 23609
23623 and 23629
23627 and 23633
23663 and 23669
23671 and 23677
23741 and 23747
23747 and 23753
23761 and 23767
23767 and 23773
23813 and 23819
23827 and 23833
23873 and 23879
23887 and 23893
23893 and 23899
23911 and 23917
23971 and 23977
24001 and 24007
24023 and 24029
24043 and 24049
24071 and 24077
24077 and 24083
24091 and 24097
24097 and 24103
24103 and 24109
24107 and 24113
24197 and 24203
24223 and 24229
24373 and 24379
24407 and 24413
24413 and 24419
24527 and 24533
24671 and 24677
24677 and 24683
24691 and 24697
24793 and 24799
24841 and 24847
24917 and 24923
24971 and 24977
25031 and 25037
25111 and 25117
25121 and 25127
25147 and 25153
25163 and 25169
25183 and 25189
25237 and 25243
25247 and 25253
25301 and 25307
25303 and 25309
25343 and 25349
25367 and 25373
25447 and 25453
25457 and 25463
25463 and 25469
25577 and 25583
25583 and 25589
25603 and 25609
25633 and 25639
25667 and 25673
25673 and 25679
25741 and 25747
25793 and 25799
25841 and 25847
25867 and 25873
25913 and 25919
25933 and 25939
25997 and 26003
26107 and 26113
26113 and 26119
26171 and 26177
26177 and 26183
26183 and 26189
26203 and 26209
26261 and 26267
26387 and 26393
26393 and 26399
26417 and 26423
26431 and 26437
26591 and 26597
26627 and 26633
26641 and 26647
26681 and 26687
26687 and 26693
26693 and 26699
26711 and 26717
26717 and 26723
26723 and 26729
26731 and 26737
26777 and 26783
26833 and 26839
26921 and 26927
26947 and 26953
26953 and 26959
26981 and 26987
26987 and 26993
27011 and 27017
27061 and 27067
27067 and 27073
27103 and 27109
27191 and 27197
27253 and 27259
27271 and 27277
27277 and 27283
27361 and 27367
27431 and 27437
27481 and 27487
27611 and 27617
27647 and 27653
27691 and 27697
27733 and 27739
27737 and 27743
27743 and 27749
27767 and 27773
27773 and 27779
27793 and 27799
27803 and 27809
27817 and 27823
27941 and 27947
27947 and 27953
27961 and 27967
28051 and 28057
28081 and 28087
28277 and 28283
28283 and 28289
28387 and 28393
28403 and 28409
28433 and 28439
28493 and 28499
28541 and 28547
28573 and 28579
28591 and 28597
28597 and 28603
28621 and 28627
28643 and 28649
28657 and 28663
28663 and 28669
28697 and 28703
28723 and 28729
28753 and 28759
28807 and 28813
28837 and 28843
28921 and 28927
28927 and 28933
29017 and 29023
29021 and 29027
29027 and 29033
29123 and 29129
29131 and 29137
29147 and 29153
29167 and 29173
29173 and 29179
29201 and 29207
29297 and 29303
29327 and 29333
29333 and 29339
29383 and 29389
29423 and 29429
29437 and 29443
29531 and 29537
29567 and 29573
29581 and 29587
29663 and 29669
29717 and 29723
29753 and 29759
29867 and 29873
29873 and 29879
29921 and 29927
29983 and 29989
30091 and 30097
30097 and 30103
30103 and 30109
30113 and 30119
30133 and 30139
30181 and 30187
30197 and 30203
30253 and 30259
30307 and 30313
30313 and 30319
30341 and 30347
30491 and 30497
30553 and 30559
30631 and 30637
30637 and 30643
30643 and 30649
30671 and 30677
30697 and 30703
30707 and 30713
30757 and 30763
30803 and 30809
30853 and 30859
30931 and 30937
30971 and 30977
30977 and 30983
31013 and 31019
31033 and 31039
31063 and 31069
31147 and 31153
31153 and 31159
31177 and 31183
31183 and 31189
31231 and 31237
31247 and 31253
31253 and 31259
31271 and 31277
31321 and 31327
31327 and 31333
31387 and 31393
31391 and 31397
31511 and 31517
31541 and 31547
31567 and 31573
31601 and 31607
31643 and 31649
31657 and 31663
31721 and 31727
31723 and 31729
31793 and 31799
31957 and 31963
32003 and 32009
32051 and 32057
32057 and 32063
32063 and 32069
32077 and 32083
32083 and 32089
32183 and 32189
32251 and 32257
32297 and 32303
32303 and 32309
32321 and 32327
32353 and 32359
32363 and 32369
32371 and 32377
32423 and 32429
32491 and 32497
32497 and 32503
32531 and 32537
32563 and 32569
32573 and 32579
32603 and 32609
32647 and 32653
32687 and 32693
32707 and 32713
32713 and 32719
32783 and 32789
32797 and 32803
32833 and 32839
32911 and 32917
32933 and 32939
32987 and 32993
32993 and 32999
33023 and 33029
33107 and 33113
33113 and 33119
33311 and 33317
33343 and 33349
33347 and 33353
33353 and 33359
33403 and 33409
33487 and 33493
33563 and 33569
33581 and 33587
33613 and 33619
33617 and 33623
33623 and 33629
33641 and 33647
33751 and 33757
33767 and 33773
33791 and 33797
33851 and 33857
33857 and 33863
33931 and 33937
33961 and 33967
34033 and 34039
34123 and 34129
34141 and 34147
34211 and 34217
34253 and 34259
34261 and 34267
34267 and 34273
34297 and 34303
34313 and 34319
34361 and 34367
34513 and 34519
34537 and 34543
34543 and 34549
34583 and 34589
34607 and 34613
34667 and 34673
34673 and 34679
34687 and 34693
34757 and 34763
34841 and 34847
34843 and 34849
34871 and 34877
34877 and 34883
34913 and 34919
35053 and 35059
35083 and 35089
35111 and 35117
35153 and 35159
35221 and 35227
35251 and 35257
35311 and 35317
35317 and 35323
35401 and 35407
35521 and 35527
35527 and 35533
35531 and 35537
35537 and 35543
35591 and 35597
35597 and 35603
35671 and 35677
35747 and 35753
35753 and 35759
35797 and 35803
35803 and 35809
35831 and 35837
35863 and 35869
35963 and 35969
35977 and 35983
35993 and 35999
36007 and 36013
36011 and 36017
36061 and 36067
36067 and 36073
36131 and 36137
36263 and 36269
36293 and 36299
36307 and 36313
36313 and 36319
36383 and 36389
36451 and 36457
36467 and 36473
36473 and 36479
36523 and 36529
36637 and 36643
36671 and 36677
36677 and 36683
36691 and 36697
36761 and 36767
36781 and 36787
36787 and 36793
36871 and 36877
36913 and 36919
36923 and 36929
36973 and 36979
36997 and 37003
37013 and 37019
37117 and 37123
37217 and 37223
37307 and 37313
37357 and 37363
37363 and 37369
37441 and 37447
37483 and 37489
37501 and 37507
37511 and 37517
37561 and 37567
37567 and 37573
37573 and 37579
37643 and 37649
37657 and 37663
37693 and 37699
37847 and 37853
37951 and 37957
37957 and 37963
37987 and 37993
37991 and 37997
38047 and 38053
38113 and 38119
38177 and 38183
38183 and 38189
38231 and 38237
38281 and 38287
38321 and 38327
38327 and 38333
38371 and 38377
38447 and 38453
38453 and 38459
38561 and 38567
38603 and 38609
38671 and 38677
38693 and 38699
38707 and 38713
38723 and 38729
38833 and 38839
38861 and 38867
38867 and 38873
38917 and 38923
38953 and 38959
38971 and 38977
39041 and 39047
39097 and 39103
39107 and 39113
39113 and 39119
39133 and 39139
39157 and 39163
39227 and 39233
39233 and 39239
39317 and 39323
39367 and 39373
39503 and 39509
39563 and 39569
39703 and 39709
39727 and 39733
39821 and 39827
39841 and 39847
39857 and 39863
39863 and 39869
39877 and 39883
39983 and 39989
40031 and 40037
40087 and 40093
40093 and 40099
40123 and 40129
40163 and 40169
40231 and 40237
40277 and 40283
40283 and 40289
40351 and 40357
40423 and 40429
40427 and 40433
40487 and 40493
40493 and 40499
40577 and 40583
40591 and 40597
40693 and 40699
40813 and 40819
40823 and 40829
40841 and 40847
40847 and 40853
40897 and 40903
40927 and 40933
40933 and 40939
41011 and 41017
41017 and 41023
41051 and 41057
41143 and 41149
41177 and 41183
41183 and 41189
41221 and 41227
41227 and 41233
41257 and 41263
41263 and 41269
41351 and 41357
41381 and 41387
41507 and 41513
41513 and 41519
41543 and 41549
41597 and 41603
41603 and 41609
41611 and 41617
41621 and 41627
41641 and 41647
41681 and 41687
41771 and 41777
41843 and 41849
41887 and 41893
41897 and 41903
41941 and 41947
41947 and 41953
41953 and 41959
42013 and 42019
42017 and 42023
42083 and 42089
42181 and 42187
42187 and 42193
42221 and 42227
42293 and 42299
42331 and 42337
42373 and 42379
42391 and 42397
42397 and 42403
42403 and 42409
42437 and 42443
42451 and 42457
42457 and 42463
42461 and 42467
42467 and 42473
42571 and 42577
42643 and 42649
42677 and 42683
42683 and 42689
42697 and 42703
42703 and 42709
42737 and 42743
42767 and 42773
42787 and 42793
42853 and 42859
42923 and 42929
42937 and 42943
42961 and 42967
43013 and 43019
43201 and 43207
43313 and 43319
43391 and 43397
43397 and 43403
43451 and 43457
43481 and 43487
43573 and 43579
43591 and 43597
43607 and 43613
43627 and 43633
43711 and 43717
43753 and 43759
43777 and 43783
43781 and 43787
43783 and 43789
43787 and 43793
43963 and 43969
43991 and 43997
44021 and 44027
44053 and 44059
44123 and 44129
44201 and 44207
44257 and 44263
44263 and 44269
44267 and 44273
44273 and 44279
44351 and 44357
44383 and 44389
44491 and 44497
44501 and 44507
44531 and 44537
44537 and 44543
44543 and 44549
44617 and 44623
44641 and 44647
44651 and 44657
44771 and 44777
44887 and 44893
44953 and 44959
45007 and 45013
45077 and 45083
45121 and 45127
45131 and 45137
45191 and 45197
45337 and 45343
45427 and 45433
45433 and 45439
45491 and 45497
45497 and 45503
45667 and 45673
45691 and 45697
45751 and 45757
45757 and 45763
45817 and 45823
45821 and 45827
45827 and 45833
45863 and 45869
45887 and 45893
45943 and 45949
45953 and 45959
46021 and 46027
46093 and 46099
46141 and 46147
46147 and 46153
46181 and 46187
46273 and 46279
46301 and 46307
46441 and 46447
46451 and 46457
46471 and 46477
46567 and 46573
46633 and 46639
46643 and 46649
46681 and 46687
46751 and 46757
46811 and 46817
46861 and 46867
47051 and 47057
47087 and 47093
47123 and 47129
47137 and 47143
47143 and 47149
47287 and 47293
47297 and 47303
47303 and 47309
47381 and 47387
47491 and 47497
47501 and 47507
47507 and 47513
47521 and 47527
47527 and 47533
47563 and 47569
47623 and 47629
47653 and 47659
47711 and 47717
47737 and 47743
47791 and 47797
47837 and 47843
47911 and 47917
47933 and 47939
47963 and 47969
48017 and 48023
48023 and 48029
48073 and 48079
48157 and 48163
48187 and 48193
48407 and 48413
48473 and 48479
48481 and 48487
48491 and 48497
48527 and 48533
48533 and 48539
48673 and 48679
48751 and 48757
48761 and 48767
48781 and 48787
48817 and 48823
48883 and 48889
48947 and 48953
49003 and 49009
49031 and 49037
49037 and 49043
49103 and 49109
49117 and 49123
49171 and 49177
49193 and 49199
49201 and 49207
49333 and 49339
49363 and 49369
49411 and 49417
49523 and 49529
49531 and 49537
49597 and 49603
49627 and 49633
49633 and 49639
49663 and 49669
49741 and 49747
49783 and 49789
49801 and 49807
49871 and 49877
49921 and 49927
49937 and 49943
49993 and 49999
There were 1419 sexy prime pairs displayed between 1 and 50000
The Sieve of Eratosthenes!
The Sieve of Eratosthenes is an ancient algorithm for finding all prime numbers up to a specific number from the set of integers. We use this to find a second mathematical series called Sexy Twins or Sexy Primes (from the Latin for six) or sets of prime numbers which are only 6 digits apart like the numbers 7 and 13. You will need to enter an upper and lower boundary between 1 and 50000. We'll give you the Sexy Primes between them.
Please enter a lower boundary and an upper boundary and I will print all of the sexy prime pairs between those boundaries.
Please enter the lower boundary (between 1 and 50000): 5
Please enter the upper boundary (between 1 and 50000): 100
5 and 11
7 and 13
11 and 17
13 and 19
17 and 23
23 and 29
31 and 37
37 and 43
41 and 47
47 and 53
53 and 59
61 and 67
67 and 73
73 and 79
83 and 89
There were 15 sexy prime pairs displayed between 5 and 100
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