A316090 a(n) = [x^n] (Sum_{k=0..n} (k*x)^k)/(Sum_{k=0..n} (-k*x)^k).

1, 2, 2, 48, 94, 5694, 12352, 1539850, 3323890, 737028224, 1556371198, 548747031342, 1138137849328, 586694732526026, 1202647898994626, 852409708509446800, 1734703213512100766, 1616070775292699964094, 3273912763003648926368, 3875483980992048140938410

Offset

0,2

Links

Seiichi Manyama, Table of n, a(n) for n = 0..386

Formula

a(n) ~ 4 * exp(-1) * n^(n-1) if n is even and a(n) ~ 2 * n^n if n is odd. - Vaclav Kotesovec, Jun 25 2018

Prog

(PARI) N=66; x='x+O('x^N); Vec((sum(k=0, N, (k*x)^k))/(sum(k=0, N, (-k*x)^k)))

Crossrefs

Cf. A000312, A296715, A303565.

Sequence in context: A086204 A318085 A345267 * A345463 A322106 A321693

Adjacent sequences: A316087 A316088 A316089 * A316091 A316092 A316093

Keyword

nonn

Author

Seiichi Manyama, Jun 24 2018

Status

approved