A172976 Primes p such that 2p - 1 and 6p - 1 are prime.

2, 3, 7, 19, 157, 199, 229, 379, 439, 577, 829, 877, 967, 997, 1009, 1279, 1429, 1459, 1657, 2137, 2539, 3067, 3169, 3187, 3319, 3739, 3769, 3967, 4159, 4357, 4447, 4909, 4987, 6079, 6379, 6427, 6709, 6967, 7219, 7297, 7639, 8209, 9049, 9067, 9157, 9277

Offset

1,1

Links

Iain Fox, Table of n, a(n) for n = 1..10000

Prog

(Magma) [p: p in PrimesUpTo(10000)|IsPrime(2*p-1) and IsPrime(6*p-1)] // Vincenzo Librandi, Jan 29 2011
(PARI) lista(nn) = forprime(p=2, nn, if(isprime(2*p - 1) && isprime(6*p - 1), print1(p, ", "))) \\ Iain Fox, Jan 20 2018

Crossrefs

Sequence in context: A075487 A110498 A244917 * A171655 A293683 A006073

Adjacent sequences: A172973 A172974 A172975 * A172977 A172978 A172979

Keyword

nonn,easy,less

Author

Juri-Stepan Gerasimov, Feb 06 2010

Extensions

Corrected and extended by Charles R Greathouse IV, Mar 25 2010

Status

approved