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A307569
Expansion of Product_{j>=1} (1 + x^j*Product_{k>=1} (1 + x^k)^j).
1
1, 1, 2, 5, 13, 31, 77, 188, 458, 1113, 2693, 6494, 15614, 37441, 89563, 213771, 509166, 1210327, 2871563, 6800559, 16077631, 37948242, 89432015, 210456759, 494577391, 1160743593, 2720787358, 6369890095, 14895975508, 34795635421, 81192795264, 189262428612, 440739646423, 1025383979625
OFFSET
0,3
FORMULA
G.f.: g(x*g(x)), where g(x) = g.f. of A000009.
MATHEMATICA
nmax = 33; CoefficientList[Series[Product[(1 + x^j Product[(1 + x^k)^j, {k, 1, nmax}]), {j, 1, nmax}], {x, 0, nmax}], x]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Apr 15 2019
STATUS
approved