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A366718
Largest prime factor of 12^n - 1.
4
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
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]];
KEYWORD
nonn
AUTHOR
Sean A. Irvine, Oct 17 2023
STATUS
approved