OFFSET
1,1
COMMENTS
Primes in A236171. All primes appear to end in a 1 or a 9 (congruent to either 1 mod 10 or 9 mod 10).
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
228901 is prime, 228901^2 - 228901 - 1 is prime, 228901^3 - 228901 - 1 is prime, and 228901^4 - 228901 - 1 is prime. So 228901 is a member of this sequence.
MATHEMATICA
Select[Prime[Range[32000]], AllTrue[#^{2, 3, 4}-#-1, PrimeQ]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Apr 08 2019 *)
PROG
(Python)
import sympy
from sympy import isprime
{print(p) for p in range(10**6) if isprime(p) and isprime(p**2-p-1) and isprime(p**3-p-1) and isprime(p**4-p-1)}
(PARI)
s=[]; forprime(p=2, 400000, if(isprime(p^2-p-1) && isprime(p^3-p-1) && isprime(p^4-p-1), s=concat(s, p))); s \\ Colin Barker, Jan 20 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Derek Orr, Jan 19 2014
STATUS
approved