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A366613
Sum of the divisors of 5^n-1.
11
7, 60, 224, 1736, 6048, 49920, 136724, 1107792, 3718400, 27060480, 85449224, 869499904, 2136230474, 15820920000, 61359427584, 461863805760, 1338408456700, 13177159680000, 33558717136896, 301282248701952, 863701914880000, 6313641012910080, 20863951122979048
OFFSET
1,1
LINKS
FORMULA
a(n) = sigma(5^n-1) = A000203(A024049(n)).
EXAMPLE
a(3)=224 because 5^3-1 has divisors {1, 2, 4, 31, 62, 124}.
MAPLE
a:=n->numtheory[sigma](5^n-1):
seq(a(n), n=1..100);
MATHEMATICA
DivisorSigma[1, 5^Range[30]-1]
KEYWORD
nonn
AUTHOR
Sean A. Irvine, Oct 14 2023
STATUS
approved