OFFSET
1,2
COMMENTS
Inverse Euler transform of A000225.
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 1..1000
FORMULA
-1 + Product_{n>=1} 1/(1 - x^n)^a(n) = g.f. of A000225.
a(n) ~ 2^n/n. - Vaclav Kotesovec, May 28 2019
MATHEMATICA
nmax = 38; CoefficientList[Series[Sum[MoebiusMu[k] Log[1 + x^k/((1 - x^k) (1 - 2 x^k))]/k, {k, 1, nmax}], {x, 0, nmax}], x] // Rest
nmax = 50; s = ConstantArray[0, nmax]; Do[s[[j]] = j*(2^ j - 1) - Sum[s[[d]]*(2^(j - d) - 1), {d, 1, j - 1}], {j, 1, nmax}]; Table[Sum[MoebiusMu[k/d]*s[[d]], {d, Divisors[k]}]/k, {k, 1, nmax}] (* Vaclav Kotesovec, Aug 10 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, May 27 2019
STATUS
approved