OFFSET
0,3
COMMENTS
Weigh transform of A069735.
FORMULA
MATHEMATICA
nmax = 41; CoefficientList[Series[Product[((1 - x^(4 k))/(1 - x^k))^DivisorSigma[0, k], {k, 1, nmax}], {x, 0, nmax}], x]
a[n_] := a[n] = If[n == 0, 1, Sum[Sum[(-1)^(k/d + 1) d If[EvenQ[d], DivisorSigma[0, d] + DivisorSigma[0, d/2], DivisorSigma[0, d]], {d, Divisors[k]}] a[n - k], {k, 1, n}]/n]; Table[a[n], {n, 0, 41}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Nov 13 2019
STATUS
approved