|
|
A236073
|
|
Primes p such that p^4 + p + 1 and p^4 - p - 1 are also prime.
|
|
0
|
|
|
2, 5, 11, 239, 1871, 4001, 4397, 6971, 12647, 12689, 13337, 13619, 15401, 19391, 19559, 19739, 20201, 20297, 22871, 22937, 28307, 30029, 32561, 36299, 36929, 39569, 44279, 45497, 47441, 48767, 50069, 53897, 55871
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
COMMENTS
|
|
|
LINKS
|
|
|
EXAMPLE
|
6971 is prime, 6971^4 - 6971 - 1 is prime, and 6971^4 + 6971 + 1 is prime. So 6971 is a member of this sequence.
|
|
PROG
|
(Python)
import sympy
from sympy import isprime
{print(p) for p in range(10**5) if isprime(p**4+p+1) and isprime(p**4-p-1) and isprime(p)}
(PARI) s=[]; forprime(p=2, 55871, if(isprime(p^4+p+1)&&isprime(p^4-p-1), s=concat(s, p))); s \\ Colin Barker, Jan 19 2014
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|