A009345 Expansion of log(1+sinh(log(1+x))).

0, 1, -2, 8, -45, 324, -2850, 29700, -358470, 4924080, -75909960, 1298430000, -24410370600, 500392015200, -11109296998800, 265568231728800, -6801224604174000, 185781460921056000, -5391780968862288000

Offset

0,3

Links

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

Formula

a(n) ~ (n-1)! * (-1)^(n+1) * (1+1/sqrt(2))^n. - Vaclav Kotesovec, Jan 23 2015

Mathematica

Log[ 1+Sinh[ Log[ 1+x ] ] ]
CoefficientList[Series[Log[(2 + 4*x + x^2)/(2 + 2*x)], {x, 0, 20}], x] * Range[0, 20]! (* Vaclav Kotesovec, Jan 23 2015 *)

Crossrefs

Sequence in context: A152401 A325138 A358436 * A084553 A144164 A003091

Adjacent sequences: A009342 A009343 A009344 * A009346 A009347 A009348

Keyword

sign,easy

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Status

approved