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A009409 Expansion of log(1+x)*cos(tanh(x)). 0
0, 1, -1, -1, 0, 49, -165, -393, -504, 66753, -414225, 21295, -15435816, 561504241, -5685997317, 34755442407, -746778152400, 18822723988481, -281687621998401, 3781703063806559, -80079140948241200, 1899387285774263089 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,6

LINKS

Table of n, a(n) for n=0..21.

FORMULA

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

MATHEMATICA

With[{nn=25}, CoefficientList[Series[Log[1+x]*Cos[Tanh[x]], {x, 0, nn}], x]Range[0, nn]!] (* Harvey P. Dale, Oct 11 2011 *)

CROSSREFS

Sequence in context: A338011 A066551 A134210 * A009431 A226353 A074216

Adjacent sequences: A009406 A009407 A009408 * A009410 A009411 A009412

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 February 7 02:40 EST 2023. Contains 360111 sequences. (Running on oeis4.)