OFFSET
1,2
EXAMPLE
a(12) = a(2^2 * 3^1) = (2 + 3)^(2 * 1) = 25.
MATHEMATICA
Table[DivisorSum[n, # &, PrimeQ[#] &]^DivisorSigma[0, n/Last[Select[Divisors[n], SquareFreeQ]]], {n, 75}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Feb 07 2019
STATUS
approved