A306910 Expansion of Sum_{k>=0} x^(k^2) * Product_{j=1..k} (1 + j*x^j).

1, 1, 1, 0, 1, 1, 2, 2, 0, 1, 1, 2, 5, 3, 6, 6, 1, 1, 2, 5, 7, 10, 14, 20, 12, 25, 25, 2, 5, 7, 15, 19, 30, 37, 59, 74, 71, 101, 62, 125, 127, 15, 25, 36, 49, 89, 116, 160, 214, 241, 343, 476, 449, 427, 615, 385, 763, 776, 103, 151, 209, 319, 415, 594, 818, 1068, 1234, 1725

Offset: 0

Author

Ilya Gutkovskiy, Mar 16 2019

Keywords

• nonn

Crossrefs

Cf. A306707, A306734, A318770.

Programs

Mathematica

nmax = 67; CoefficientList[Series[Sum[x^(k^2) Product[(1 + j x^j), {j, 1, k}], {k, 0, nmax}], {x, 0, nmax}], x]