OFFSET
1,1
EXAMPLE
3 is prime. 3^5-3^4-3^3-3^2-3-1 = 122 and 122^5-122^4-122^3-122^2-122-1 = 26803717321 is a prime number. Thus, 3 is a member of this sequence.
PROG
(Python)
import sympy
from sympy import isprime, primerange
def f(x):
return x**5-x**4-x**3-x**2-x-1
[p for p in primerange(2, 10**5) if isprime(f(f(p)))]
CROSSREFS
KEYWORD
nonn
AUTHOR
Derek Orr, Feb 26 2014
STATUS
approved