%I #10 Mar 05 2014 17:35:00

%S 3,487,547,877,1063,1291,1579,1657,2287,2797,3343,3793,4909,4957,6163,

%T 6571,7393,8461,8521,8563,9631,11257,11863,12211,12757,12907,13063,

%U 13567,13999,14983,15427,15739,16087,16651,16699,17419,17713,17977

%N Primes p such that f(f(p)) is prime, where f(x) = x^4-x^3-x^2-x-1.

%e 3 is prime and (3^4-3^3-3^2-3-1)^4 - (3^4-3^3-3^2-3-1)^3 - (3^4-3^3-3^2-3-1)^2 - (3^4-3^3-3^2-3-1) - 1 = 2755117 is prime. Thus, 3 is a member of this sequence.

%o (Python)

%o import sympy

%o from sympy import isprime

%o def f(x):

%o ..return x**4-x**3-x**2-x-1

%o {print(p) for p in range(10**5) if isprime(p) and isprime(f(f(p)))}

%Y Cf. A000040, A237639, A125082.

%K nonn

%O 1,1

%A _Derek Orr_, Feb 23 2014