A380030 Expansion of e.g.f. (1 - 3*x*exp(x))^(2/3).

1, -2, -6, -26, -208, -2570, -42332, -865718, -21110224, -597416786, -19239912340, -694646155742, -27785653906232, -1219574936748506, -58274685177526300, -3011159013528002150, -167299112903683007392, -9945379044947061586850, -629870278061691615041828

Offset

0,2

Links

Table of n, a(n) for n=0..18.

Formula

a(n) = n! * Sum_{k=0..n} (-3)^k * k^(n-k) * binomial(2/3,k)/(n-k)!.

Prog

(PARI) a(n) = n!*sum(k=0, n, (-3)^k*k^(n-k)*binomial(2/3, k)/(n-k)!);

Crossrefs

Cf. A004989, A380029.

Sequence in context: A007139 A306147 A331937 * A162438 A137071 A255016

Adjacent sequences: A380026 A380028 A380029 * A380031 A380032 A380033

Keyword

sign,easy

Author

Seiichi Manyama, Jan 09 2025

Status

approved