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A009781 Expansion of e.g.f.: tanh(log(1+x))/cosh(x). 1
0, 1, -1, -3, 12, -5, -75, 203, -1232, 16245, -44685, -957671, 11106876, -34555105, -281002631, 4852910775, -67849574400, 823102605865, -1467960664185, -158552006816779, 2993025524196940, -21779819623624125 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..200

MATHEMATICA

With[{nn=30}, CoefficientList[Series[Tanh[Log[1+x]]/Cosh[x], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Nov 12 2013 *)

CROSSREFS

Sequence in context: A085296 A306364 A214401 * A266913 A307027 A304566

Adjacent sequences:  A009778 A009779 A009780 * A009782 A009783 A009784

KEYWORD

sign,easy

AUTHOR

R. H. Hardin

EXTENSIONS

Extended with signs by Olivier Gérard, Mar 15 1997

Definition clarified and previous Mathematica program replaced by Harvey P. Dale, Nov 12 2013

STATUS

approved

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Last modified June 16 21:20 EDT 2019. Contains 324155 sequences. (Running on oeis4.)