A307571 Expansion of Product_{j>=1} (1 + x^j*Product_{k>=1} (1 + x^k)^(k*j))^j.

1, 1, 3, 11, 38, 129, 436, 1445, 4764, 15583, 50667, 163890, 527620, 1691368, 5400754, 17183173, 54487190, 172235992, 542844404, 1706169816, 5348478123, 16724698483, 52174714116, 162399459964, 504402061533, 1563430065203, 4836462927829, 14933470162894, 46026742326000, 141614337715832

Offset

0,3

Links

Table of n, a(n) for n=0..29.

Formula

G.f.: g(x*g(x)), where g(x) = g.f. of A026007.

Mathematica

nmax = 29; CoefficientList[Series[Product[(1 + x^j Product[(1 + x^k)^(k j), {k, 1, nmax}])^j, {j, 1, nmax}], {x, 0, nmax}], x]

Crossrefs

Cf. A026007, A307323, A307569, A307570.

Sequence in context: A092201 A273526 A026943 * A047096 A149060 A151468

Adjacent sequences: A307568 A307569 A307570 * A307572 A307573 A307574

Keyword

nonn

Author

Ilya Gutkovskiy, Apr 15 2019

Status

approved