A091199 Numbers n such that (6n-3)^2 + 2 is prime.

1, 2, 3, 4, 6, 7, 8, 10, 14, 17, 18, 19, 20, 21, 25, 29, 37, 38, 40, 41, 42, 43, 46, 50, 51, 52, 54, 58, 59, 61, 62, 63, 65, 70, 71, 72, 74, 75, 76, 80, 84, 86, 92, 93, 94, 96, 101, 102, 109, 113, 114, 117, 119, 126, 130, 135, 137, 140, 145, 148, 150, 151, 152, 156, 160

Offset

1,2

Comments

Arises from A056899: primes of the form m^2+2; m should be of the form 6n-3, hence this sequence.

Links

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

Formula

a(n) = A056900(n-1) + 1. - Jeppe Stig Nielsen, May 14 2017

Example

10 is a member because (60-3)^2 + 2 = 3251 is prime.

Mathematica

Select[ Range[ 163], PrimeQ[(6# - 3)^2 + 2] &] (* Robert G. Wilson v, Feb 26 2004 *)
lst={}; Do[If[PrimeQ[(6n-3)^2+2], AppendTo[lst, n]], {n, 500}]; lst (* Vincenzo Librandi, Jul 16 2012 *)

Prog

(Magma) [n: n in [1..250]| IsPrime((6*n-3)^2+2)]; // Vincenzo Librandi, Jul 16 2012
(PARI) is(n)=isprime((6*n-3)^2+2) \\ Charles R Greathouse IV, May 22 2017

Crossrefs

Cf. A056899, A056900.

Sequence in context: A226038 A181062 A338031 * A093452 A082103 A219618

Adjacent sequences: A091196 A091197 A091198 * A091200 A091201 A091202

Keyword

easy,nonn

Author

Zak Seidov, Feb 22 2004

Extensions

More terms from Ray Chandler and Robert G. Wilson v, Feb 25 2004

Status

approved