A134003 - OEIS

%I #6 Nov 21 2013 13:07:20

%S 1,2,3,4,6,7,8,9,12,14,17,18,19,21,22,26,27,28,29,32,34,39,41,43,44,

%T 48,51,52,53,54,56,58,59,66,72,74,77,78,79,82,83,87,91,93,94,96,97,

%U 103,104,106,107,109,113,116,117,119,121,122,123,126,134,136,137,144,151,157

%N Positive integers n for which n^2+(n+5)^2 is prime.

%C Conjecture. If n is in this sequence then n(n+5)=a(a+5)+b(b+5) is not solvable in integers. (This has been verified up to n=500.) See A134002 for the complement of this sequence (in the positive integers).

%t Select[Range[1,200],PrimeQ[#^2+(#+5)^2]&] (* _Vladimir Joseph Stephan Orlovsky_, Feb 02 2012 *)

%Y Cf. A012132, A027861, A134002.

%K nonn

%O 1,2

%A _John W. Layman_, Oct 01 2007