A366718 Largest prime factor of 12^n - 1.

11, 13, 157, 29, 22621, 157, 4943, 233, 80749, 22621, 266981089, 20593, 20369233, 13063, 22621, 260753, 74876782031, 80749, 29043636306420266077, 85403261, 8177824843189, 57154490053, 321218438243, 2227777, 12629757106815551, 20369233, 86769286104133

Offset

1,1

Links

Max Alekseyev, Table of n, a(n) for n = 1..310

J. Brillhart et al., Factorizations of b^n +- 1, Contemporary Mathematics, Vol. 22, Amer. Math. Soc., Providence, RI, 3rd edition, 2002.

Formula

a(n) = A006530(A024140(n)).

Mathematica

Table[FactorInteger[12^n - 1][[-1, 1]], {n, 40}]

Prog

(Magma) [Maximum(PrimeDivisors(12^n-1)): n in [1..40]];

Crossrefs

Cf. A024140, A006530, A005420, A074477, A274906, A074479, A274907, A074249, A274908, A274909, A005422, A274910, A366707, A366708, A366709, A366710, A366711, A366717, A366720.

Sequence in context: A094621 A178426 A252170 * A144375 A140969 A064759

Adjacent sequences: A366715 A366716 A366717 * A366719 A366720 A366721

Keyword

nonn

Author

Sean A. Irvine, Oct 17 2023

Status

approved