OFFSET
1,2
COMMENTS
Inverse Moebius transform of A007294.
MATHEMATICA
nmax = 60; CoefficientList[Series[Sum[-1 + Product[1/(1 - x^(k j (j + 1)/2)), {j, 1, nmax}], {k, 1, nmax}], {x, 0, nmax}], x] // Rest
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Nov 13 2019
STATUS
approved