login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A271666
Primes p such that 4*p^2+4*p-1 is prime.
2
2, 3, 7, 13, 17, 23, 31, 37, 53, 59, 67, 139, 149, 151, 157, 167, 179, 193, 199, 223, 233, 293, 307, 331, 359, 373, 389, 431, 479, 571, 587, 619, 643, 653, 683, 809, 839, 857, 863, 919, 937, 947, 1021, 1091, 1123, 1151, 1187, 1277, 1301, 1367, 1427, 1511
OFFSET
1,1
LINKS
MATHEMATICA
Select[Prime[Range[300]], PrimeQ[4 #^2 + 4 # - 1] &]
PROG
(Magma) [p: p in PrimesUpTo(2000) | IsPrime(4*p^2+4*p-1)];
(PARI) lista(nn) = forprime(p=2, nn, if(isprime(4*p^2+4*p-1), print1(p, ", "))); \\ Altug Alkan, Apr 12 2016
(Python)
from gmpy2 import is_prime
for p in range(3, 10**5, 2):
if(not is_prime(p)):continue
elif(is_prime(6*p**2+6*p-1)):print(p)
# Soumil Mandal, Apr 14 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Apr 12 2016
STATUS
approved