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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Table of n, a(n) for n=0..19.

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

Adjacent sequences:  A009362 A009363 A009364 * A009366 A009367 A009368

KEYWORD

sign,easy

AUTHOR

R. H. Hardin

EXTENSIONS

Extended with signs by Olivier Gérard, Mar 15 1997

STATUS

approved

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Last modified August 11 06:25 EDT 2020. Contains 336422 sequences. (Running on oeis4.)