A366719 Smallest prime dividing 12^n + 1.

2, 13, 5, 7, 89, 13, 5, 13, 17, 7, 5, 13, 89, 13, 5, 7, 153953, 13, 5, 13, 41, 7, 5, 13, 17, 13, 5, 7, 89, 13, 5, 13, 769, 7, 5, 13, 89, 13, 5, 7, 17, 13, 5, 13, 89, 7, 5, 13, 7489, 13, 5, 7, 89, 13, 5, 13, 17, 7, 5, 13, 41, 13, 5, 7, 36097, 13, 5, 13, 89, 7

Offset: 0

Author

Sean A. Irvine, Oct 17 2023

Keywords

• nonn

Links

• Max Alekseyev, Table of n, a(n) for n = 0..511

Crossrefs

Cf. A002586, A038371, A178248, A366712, A366713, A366714, A366715, A366716, A366717, A366720.

Programs

Mathematica

Table[FactorInteger[12^n + 1][[1,1]], {n, 0, 69}] (* Paul F. Marrero Romero, Oct 25 2023 *)

Formula

a(n) = A020639(A178248(n)). - Paul F. Marrero Romero, Oct 25 2023