A366720 Largest prime factor of 12^n+1.

2, 13, 29, 19, 233, 19141, 20593, 13063, 260753, 1801, 85403261, 57154490053, 2227777, 222379, 13156924369, 35671, 1200913648289, 66900193189411, 122138321401, 905265296671, 67657441, 1885339, 68368660537, 49489630860836437, 592734049, 438472201

Offset: 0

Author

Sean A. Irvine, Oct 17 2023

Keywords

• nonn

Links

• Max Alekseyev, Table of n, a(n) for n = 0..306

Crossrefs

Cf. A178248, A006530, A002587, A074476, A274903, A074478, A274904, A227575, A274905, A002592, A003021, A062308, A002590, A366712, A366713, A366714, A366715, A366716, A366717, A366718, A366719, A324941.

Programs

Mathematica

Table[FactorInteger[12^n + 1][[-1, 1]], {n, 0, 20}]

Formula

a(n) = A006530(A178248(n)). - Paul F. Marrero Romero, Dec 07 2023