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A366617
Sum of the divisors of 5^n+1.
9
3, 12, 42, 312, 942, 6264, 25284, 162000, 620460, 4961280, 16161768, 103442688, 367381884, 2441936064, 9859525284, 76963663296, 228970112844, 1526377433328, 6339280635408, 38199227335200, 144103649734968, 1285221510144000, 3894650946433800, 24349131482713344
OFFSET
0,1
LINKS
FORMULA
a(n) = sigma(5^n+1) = A000203(A034474(n)).
EXAMPLE
a(3)=312 because 5^3+1 has divisors {1, 2, 3, 6, 7, 9, 14, 18, 21, 42, 63, 126}.
MAPLE
a:=n->numtheory[sigma](5^n+1):
seq(a(n), n=0..100);
MATHEMATICA
DivisorSigma[1, 5^Range[0, 30] + 1] (* Paolo Xausa, Jul 03 2024 *)
KEYWORD
nonn
AUTHOR
Sean A. Irvine, Oct 14 2023
STATUS
approved