A165811 Primes of the form 18*p+1, where p is also a prime.

37, 127, 199, 307, 523, 739, 1063, 1279, 1423, 1747, 2287, 2467, 2503, 2683, 2719, 3259, 3547, 3583, 4339, 4519, 4987, 5059, 5527, 6067, 6247, 6607, 6823, 7219, 7759, 8623, 8839, 9739, 10243, 10567, 11863, 12619, 12763, 13627, 14347, 14563, 14779, 14887

Offset: 1

Author

Vincenzo Librandi, Sep 28 2009

Keywords

• nonn
• easy

Examples

			p=2 contributes 37=18*2+1. p=7 contributes 127=18*7+1. p=11 contributes 199=18*11+1
		

Links

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

Crossrefs

Cf. A111094, A153400, A165810.

Programs

Magma

[a: p in PrimesInInterval(2, 1000) | IsPrime(a) where a is 18*p + 1]; // Vincenzo Librandi, Oct 13 2012

Mathematica

Select[Table[18p + 1, {p, Prime[Range[400]]}], PrimeQ] (* Vincenzo Librandi, Oct 13 2012 *)

Formula

a(n) = 1+18*A165810(n).

Extensions

Extended by R. J. Mathar, Oct 16 2009