A099007 Primes of the form 6n^2 - 2n - 1.

3, 19, 47, 139, 367, 467, 839, 1319, 1699, 1907, 3407, 4003, 4987, 6079, 7703, 10499, 11527, 13159, 16747, 17387, 19379, 23687, 25219, 26003, 30103, 32707, 33599, 35419, 38239, 44203, 50599, 53959, 55103, 57427, 62219, 69767, 72379, 76387

Offset: 1

Author

Giovanni Teofilatto, Nov 07 2004

Keywords

• nonn
• easy

Comments

All terms are == 3 (mod 4).

Examples

			For n = 2 we have 6*2^2 - 2*2 -1 = 19.
		

Links

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

Crossrefs

Cf. A098828.

Programs

Magma

[a: n in [0..250] | IsPrime(a) where a is 6*n^2 - 2*n - 1]; // Vincenzo Librandi, Jul 17 2012

Mathematica

Select[Table[6n^2-2n-1,{n,0,2000}],PrimeQ] (* Vincenzo Librandi, Jul 17 2012 *)

PARI

for(k=1,120,if(isprime(p=6*k^2-2*k-1),print1(p,",")))

Extensions

Edited, corrected and extended by Klaus Brockhaus, Nov 12 2004