A366628 - OEIS

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A366628

Number of divisors of 6^n+1.

2, 2, 2, 4, 2, 8, 8, 12, 4, 8, 8, 4, 4, 16, 8, 32, 8, 8, 64, 8, 8, 48, 16, 8, 16, 16, 16, 32, 32, 16, 512, 4, 8, 64, 8, 1536, 32, 16, 8, 512, 32, 16, 128, 4, 8, 128, 32, 4, 128, 64, 64, 256, 16, 32, 1024, 192, 64, 128, 8, 4, 64, 8, 4, 768, 8, 256, 2048, 32, 32

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OFFSET

0,1

LINKS

Max Alekseyev, Table of n, a(n) for n = 0..420

FORMULA

a(n) = sigma0(6^n+1) = A000005(A062394(n)).

EXAMPLE

a(3)=4 because 6^3+1 has divisors {1, 7, 31, 217}.

MAPLE

a:=n->numtheory[tau](6^n+1):

seq(a(n), n=0..100);