A271667 Primes p such that 6*p^2+6*p-1 is prime.

3, 5, 13, 41, 43, 61, 71, 73, 103, 113, 181, 223, 241, 269, 271, 283, 379, 433, 479, 491, 521, 523, 593, 619, 631, 659, 719, 839, 929, 941, 1009, 1039, 1069, 1193, 1249, 1289, 1319, 1429, 1433, 1471, 1489, 1511, 1553, 1601, 1613, 1693, 1699, 1723, 1753, 1861

Offset: 1

Author

Vincenzo Librandi, Apr 12 2016

Keywords

• nonn
• easy

Examples

			3 is a term because 3 is prime and 6*3^2+6*3-1 is 71 which is prime. 13 is a term because 13 is prime and 6*13^2+6*13-1 is 1091 which is prime. - _Soumil Mandal_, Apr 14 2016
		

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A171139, A171831, A171832, A261810, A271666.

Programs

Magma

[p: p in PrimesUpTo(2000) | IsPrime(6*p^2+6*p-1)];

Mathematica

Select[Prime[Range[300]], PrimeQ[6 #^2 + 6 # - 1] &]

PARI

lista(nn) = forprime(p=2, nn, if(isprime(6*p^2+6*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