OFFSET
0,3
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..386
FORMULA
a(n) = [x^n] exp(Sum_{k>=1} ( Sum_{d|k} d*(n^(k/d) - 1) ) * x^k/k).
a(n) ~ n^n. - Vaclav Kotesovec, Sep 27 2018
MATHEMATICA
Table[SeriesCoefficient[Product[(1 - x^k)/(1 - n x^k), {k, 1, n}], {x, 0, n}], {n, 0, 19}]
Table[SeriesCoefficient[Exp[Sum[Sum[d (n^(k/d) - 1), {d, Divisors[k]}] x^k/k, {k, 1, n}]], {x, 0, n}], {n, 0, 19}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Sep 27 2018
STATUS
approved