A172122 Primes p such that 7*p^2+7*p+1 is also prime.

2, 5, 17, 29, 59, 197, 227, 257, 317, 359, 467, 509, 569, 587, 797, 929, 1097, 1187, 1259, 1307, 1439, 1637, 1697, 1847, 1877, 1997, 2027, 2069, 2099, 2237, 2297, 2399, 2459, 2477, 2657, 2687, 2729, 2939, 3167, 3359, 3407, 3467, 3659, 3677, 4019, 4079

Offset

1,1

Links

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

Mathematica

Select[Prime[Range[3000]], PrimeQ[7 #^2 + 7 # + 1]&] (* Vincenzo Librandi, Apr 16 2013 *)

Prog

(Magma) [p: p in PrimesUpTo(4100) | IsPrime(7*p^2 + 7*p + 1)]; // Vincenzo Librandi, Apr 16 2013

Crossrefs

Cf. A171139.

Sequence in context: A244085 A019353 A106882 * A101009 A269018 A066649

Adjacent sequences: A172119 A172120 A172121 * A172123 A172124 A172125

Keyword

nonn,easy

Author

Vincenzo Librandi, Jan 26 2010

Status

approved