This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A270387 #6 Mar 16 2016 17:02:05 %S A270387 7,17,19,23,31,37,43,47,61,67,71,73,79,83,103,107,109,113,127,131,137, %T A270387 139,149,151,157,163,173,179,193,197,199,211,223,227,229,233,239,241, %U A270387 251,257,263,269,271,277,281,283,293,307,311,313,317,331,337,347,349,353,359,367 %N A270387 Primes p such that A000129(p) is not a prime number. %C A270387 Primes p such that ((1+sqrt(2))^p - (1-sqrt(2))^p) / (2*sqrt(2)) is a composite number. %o A270387 (PARI) a000129(n) = ([2, 1; 1, 0]^n)[2, 1]; %o A270387 forprime(p=2, 1e3, if(!isprime(a000129(p)), print1(p, ", "))); %Y A270387 Cf. A000129, A096650. %K A270387 nonn %O A270387 1,1 %A A270387 _Altug Alkan_, Mar 16 2016