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

1,1

Links

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

Example

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

Mathematica

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

Prog

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

Crossrefs

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

Sequence in context: A091798 A070198 A121934 * A269454 A153209 A239026

Adjacent sequences: A153809 A153810 A153811 * A153813 A153814 A153815

Keyword

nonn,easy

Author

Klaus Brockhaus, Jan 01 2009

Status

approved