A270387 - OEIS

%I #6 Mar 16 2016 17:02:05

%S 7,17,19,23,31,37,43,47,61,67,71,73,79,83,103,107,109,113,127,131,137,

%T 139,149,151,157,163,173,179,193,197,199,211,223,227,229,233,239,241,

%U 251,257,263,269,271,277,281,283,293,307,311,313,317,331,337,347,349,353,359,367

%N Primes p such that A000129(p) is not a prime number.

%C Primes p such that ((1+sqrt(2))^p - (1-sqrt(2))^p) / (2*sqrt(2)) is a composite number.

%o (PARI) a000129(n) = ([2, 1; 1, 0]^n)[2, 1];

%o forprime(p=2, 1e3, if(!isprime(a000129(p)), print1(p, ", ")));

%Y Cf. A000129, A096650.

%K nonn

%O 1,1

%A _Altug Alkan_, Mar 16 2016