OFFSET
1,1
COMMENTS
Primes of the form 2*k^2 + 2*k - 15.
MATHEMATICA
Select[Prime[Range[25000]], IntegerQ[Sqrt[2 # + 31]] &]
PROG
(Magma) [p: p in PrimesUpTo(300000) | IsSquare(2*p+31)];
(PARI) lista(nn) = forprime(p=2, nn, if (issquare(2*p+31), print1(p, ", "))); \\ Michel Marcus, Mar 22 2016
(Python)
from gmpy2 import is_prime, is_square
for p in range(3, 10**6, 2):
if(not is_square(2*p+31)):continue
elif(is_prime(p)):print(p)
# Soumil Mandal, Apr 07 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Vincenzo Librandi, Mar 22 2016
STATUS
approved