A306731 Expansion of Sum_{k>=0} x^k * Product_{j=1..k} (1 + x^j)^j.

1, 1, 2, 2, 4, 6, 10, 14, 24, 37, 56, 90, 135, 204, 316, 474, 704, 1068, 1579, 2332, 3445, 5054, 7376, 10750, 15587, 22497, 32437, 46544, 66520, 94908, 134912, 191185, 270301, 380924, 535469, 750898, 1050268, 1465284, 2039741, 2832694, 3925036, 5427381, 7488315, 10310431

Offset

0,3

Links

Table of n, a(n) for n=0..43.

Mathematica

nmax = 43; CoefficientList[Series[Sum[x^k Product[(1 + x^j)^j, {j, 1, k}], {k, 0, nmax}], {x, 0, nmax}], x]

Crossrefs

Cf. A000009, A206100, A306703.

Sequence in context: A139582 A300415 A355908 * A276059 A034410 A192682

Adjacent sequences: A306728 A306729 A306730 * A306732 A306733 A306734

Keyword

nonn

Author

Ilya Gutkovskiy, Mar 06 2019

Status

approved