Special neighbor primes: Difference between revisions
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Special neighbor primes 3-99: 13
</pre>
=={{header|C}}==
<lang c>#include<stdio.h>
#include<stdlib.h>
int isprime( int p ) {
int i;
if(p==2) return 1;
if(!(p%2)) return 0;
for(i=3; i*i<=p; i+=2) {
if(!(p%i)) return 0;
}
return 1;
}
int nextprime( int p ) {
int i=0;
if(p==0) return 2;
if(p<3) return p+1;
while(!isprime(++i + p));
return i+p;
}
int main(void) {
int p1, p2;
for(p1=3;p1<=99;p1+=2) {
p2=nextprime(p1);
if(p2<100&&isprime(p1)&&isprime(p2+p1-1)) {
printf( "%d + %d - 1 = %d\n", p1, p2, p1+p2-1 );
}
}
return 0;
}</lang>
{{out}}<pre>3 + 5 - 1 = 7
5 + 7 - 1 = 11
7 + 11 - 1 = 17
11 + 13 - 1 = 23
13 + 17 - 1 = 29
19 + 23 - 1 = 41
29 + 31 - 1 = 59
31 + 37 - 1 = 67
41 + 43 - 1 = 83
43 + 47 - 1 = 89
61 + 67 - 1 = 127
67 + 71 - 1 = 137
73 + 79 - 1 = 151
</pre>
=={{header|F_Sharp|F#}}==
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