A308806 Expansion of 1 / Sum_{k>=0} (-x)^(k*(3*k - 1)/2).

1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 8, 11, 14, 18, 23, 30, 40, 52, 67, 86, 111, 145, 188, 243, 314, 406, 527, 683, 883, 1141, 1475, 1910, 2474, 3201, 4140, 5355, 6929, 8968, 11603, 15009, 19416, 25121, 32507, 42060, 54413, 70393, 91071, 117831, 152453, 197238, 255175, 330137, 427130, 552620

Offset

0,6

Links

Table of n, a(n) for n=0..53.

Formula

G.f.: 1 / Sum_{k>=0} (-x)^A000326(k).

Mathematica

nmax = 53; CoefficientList[Series[1/Sum[(-x)^(k (3 k - 1)/2), {k, 0, nmax}], {x, 0, nmax}], x]

Crossrefs

Cf. A000041, A000326, A006950, A181324, A208061, A317665.

Sequence in context: A262527 A253773 A124067 * A060967 A218930 A350391

Adjacent sequences: A308803 A308804 A308805 * A308807 A308808 A308809

Keyword

nonn

Author

Ilya Gutkovskiy, Jun 25 2019

Status

approved