A153812 Primes p such that 6*p^2+1 is also prime.

5, 11, 59, 79, 89, 109, 131, 191, 199, 241, 269, 359, 389, 431, 439, 661, 691, 829, 859, 1019, 1109, 1181, 1249, 1319, 1439, 1621, 1759, 1789, 1831, 1949, 1979, 2011, 2081, 2111, 2179, 2341, 2371, 2389, 2441, 2459, 2671, 2699, 2861, 2999, 3169, 3229, 3251

Offset: 1

Author

Klaus Brockhaus, Jan 01 2009

Keywords

• nonn
• easy

Examples

			For prime p = 199, 6*p^2+1 = 237607 is prime.
		

Links

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

Crossrefs

Cf. A052291 (primes p such that 4p^2 + 1 is also prime).

Programs

Magma

[ p: p in PrimesUpTo(3300) | IsPrime(6*p^2+1) ];

Mathematica

Select[Prime[Range[500]], PrimeQ[(6 #^2 + 1)]&] (* Vincenzo Librandi, Apr 14 2013 *)