A098877 Least k such that 3*(6*n)^k + 1 is prime.

1, 1, 3, 1, 3, 1, 1, 3, 1, 1, 1, 14, 2, 2, 1, 3, 1, 270, 12, 2, 1, 1, 8, 1, 3, 2, 1, 2, 1, 1, 12, 1, 11, 1, 1, 2, 2, 12, 3, 2, 1, 1, 8, 2, 1, 1, 2, 3, 1, 2, 1, 1, 11, 3, 1, 1, 14, 2, 1, 16, 24, 1, 4, 1, 1, 3, 9, 3, 66, 4, 1, 1, 3, 6, 3, 3, 2, 7, 1, 3, 1, 156, 3, 2, 1, 1, 1, 12, 77, 1, 5, 1, 20, 1, 3, 2

Offset: 1

Author

Pierre CAMI, Oct 13 2004

Keywords

• nonn

Crossrefs

Cf. A098876, A111094.

Programs

Mathematica

f[n_] := Block[{k = 1}, While[ !PrimeQ[3*((6*n)^k) + 1], k++ ]; k]; Table[ f[n], {n, 96}] (* Robert G. Wilson v, Oct 21 2004 *)

Formula

a(A111094(n)) = 1. - Michel Marcus, Jul 28 2015

Extensions

More terms from Robert G. Wilson v, Oct 21 2004