A009178 Expansion of cosh(x)*cosh(log(1+x)).

1, 0, 2, -3, 19, -90, 556, -3885, 31109, -279972, 2799766, -30797415, 369569047, -4804397598, 67261566464, -1008923496945, 16142775951241, -274427191171080, 4939689441079594, -93854099380512267, 1877081987610245531

Offset

0,3

Links

Table of n, a(n) for n=0..20.

Formula

a(n) ~ n! * (-1)^n * (exp(-1) + exp(1))/4. - Vaclav Kotesovec, Jan 22 2015

Mathematica

With[{nn=20}, CoefficientList[Series[Cosh[x]Cosh[Log[1+x]], {x, 0, nn}], x]Range[0, nn]!] (* Harvey P. Dale, Feb 02 2012 *)

Crossrefs

Sequence in context: A143893 A262957 A072263 * A141508 A366357 A119344

Adjacent sequences: A009175 A009176 A009177 * A009179 A009180 A009181

Keyword

sign,easy

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Status

approved