login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A321285
Expansion of Product_{1 <= i < j} 1/(1 - x^(i*j)).
3
1, 0, 1, 1, 2, 2, 5, 4, 9, 9, 16, 17, 31, 31, 52, 59, 89, 101, 154, 172, 254, 294, 412, 483, 675, 782, 1070, 1265, 1686, 1996, 2647, 3121, 4086, 4854, 6252, 7442, 9534, 11306, 14360, 17092, 21489, 25566, 31989, 37981, 47224, 56123, 69283, 82290, 101185, 119930, 146768
OFFSET
0,5
LINKS
N. J. A. Sloane, Transforms
FORMULA
Euler transform of A056924.
G.f.: Product_{k>0} 1/(1 - x^k)^A056924(k).
MATHEMATICA
nmax = 50; CoefficientList[Series[Product[1/(1 - x^k)^Floor[DivisorSigma[0, k]/2], {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Nov 02 2018 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Nov 02 2018
STATUS
approved