A009416 Expansion of e.g.f. log(1+x)*cosh(x).

0, 1, -1, 5, -12, 49, -225, 1301, -8848, 69441, -616185, 6095429, -66475596, 792143793, -10238194057, 142633278997, -2130537219840, 33964965659649, -575573407212753, 10331348137881349, -195807849389362540, 3907452790559751857, -81892400673047263761, 1798373345567005989781, -41294565798306731368272, 989581607891834678407745

Offset

0,4

Links

Table of n, a(n) for n=0..25.

Formula

a(n) ~ (n-1)! * (-1)^(n+1) * cosh(1). - Vaclav Kotesovec, Jan 23 2015

a(n) = -(-1)^n * Sum_{k=0..floor((n-1)/2)} binomial(n,2*k) * (n-2*k-1)!. - Ilya Gutkovskiy, Apr 10 2022

Mathematica

CoefficientList[Series[Cosh[x]*Log[1 + x], {x, 0, 20}], x] * Range[0, 20]! (* Vaclav Kotesovec, Jan 23 2015 *)

Crossrefs

Cf. A009410.

Sequence in context: A211951 A356539 A009425 * A332477 A240389 A135769

Adjacent sequences: A009413 A009414 A009415 * A009417 A009418 A009419

Keyword

sign,easy

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Status

approved