OFFSET
1,1
COMMENTS
(p^4+5)/6 is an integer for all primes p>3, because then p == (1 or 5) (mod 6) as in A039704, therefore p^2 == 1 (mod 6) and finally p^4 == 1 (mod 6).
EXAMPLE
(7^4+5)/6 = 401 prime, (11^4+5)/6 = 2441 prime.
MATHEMATICA
Select[Prime[Range[10^3]], PrimeQ[(#^4 + 5) / 6] &] (* Vincenzo Librandi, Jan 21 2015 *)
PROG
(PARI) lista(nn) = {forprime(p=4, nn, if (isprime((p^4 + 5)/6), print1(p, ", ")); ); } \\ Michel Marcus, Jan 20 2015
(Magma) [p: p in PrimesInInterval(3, 4000) | IsPrime((p^4+5) div 6)]; // Vincenzo Librandi, Jan 21 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Jan 19 2015
STATUS
approved