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Seventh occurrence where (p-q)/(q-7), p and q are primes.
0

%I #4 Oct 01 2013 17:57:55

%S 47,43,53,37,113,101,29,29,173,61,89,173,43,43,137,71,59,59,29,47,71,

%T 29,53,47,59,43,53,23

%N Seventh occurrence where (p-q)/(q-7), p and q are primes.

%o (PARI) \ r is the occurrence desired 1=first,2=second etc. \d is the amount we take from q diff2sqp2(n,r,d) = { forprime(q=d+1,n, c=0; forprime(p=q+1,n, y=(p-q)/(q-d); if(y==floor(y), if(isprime(y),c++; if(c==r, print1(y",");break)) ) ) ) }

%K easy,nonn

%O 7,1

%A _Cino Hilliard_, Dec 28 2003