login
A009365
Expansion of log(1+tan(sinh(x))).
0
0, 1, -1, 5, -18, 121, -792, 7069, -67088, 763057, -9443584, 132103157, -2008841472, 33527321257, -603694522368, 11731117858573, -243894274033664, 5412661283979361, -127565755034927104, 3184128808387236581
OFFSET
0,4
FORMULA
a(n) ~ (n-1)! * (-1)^(n+1) / (log((Pi+sqrt(16+Pi^2))/4))^n. - Vaclav Kotesovec, Jan 23 2015
MATHEMATICA
Log[ 1+Tan[ Sinh[ x ] ] ]
CoefficientList[Series[Log[1 + Tan[Sinh[x]]], {x, 0, 20}], x] * Range[0, 20]! (* Vaclav Kotesovec, Jan 23 2015 *)
CROSSREFS
Sequence in context: A332467 A036688 A009348 * A140296 A278172 A204252
KEYWORD
sign,easy
AUTHOR
EXTENSIONS
Extended with signs by Olivier Gérard, Mar 15 1997
STATUS
approved