OFFSET
1,2
FORMULA
a(n) = Sum_{p|n, p prime} p^(n/p).
MATHEMATICA
nmax = 45; CoefficientList[Series[Sum[Prime[k] x^Prime[k]/(1 - Prime[k] x^Prime[k]), {k, 1, nmax}], {x, 0, nmax}], x] // Rest
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Mar 30 2025
STATUS
approved
