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 A009838 Expansion of e.g.f.: tanh(x)/(1+x). 1
 0, 1, -2, 4, -16, 96, -576, 3760, -30080, 278656, -2786560, 30298368, -363580416, 4748913664, -66484791296, 995368112128, -15925889794048, 270949991841792, -4877099853152256, 92635808324780032, -1852716166495600640 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 COMMENTS Unsigned sequence satisfies a(n)=na(n-1)+b(n-1) where b(n) is defined in A009006. E.g.f. tanh(z)/(1-z). - Mario Catalani (mario.catalani(AT)unito.it), Feb 10 2003 LINKS Vincenzo Librandi, Table of n, a(n) for n = 0..200 FORMULA |a(n)| ~ n! * tanh(1). - Vaclav Kotesovec, Sep 22 2013 MAPLE G(x):= tanh(x)/(1+x): f[0]:=G(x): for n from 1 to 21 do f[n]:=diff(f[n-1], x) od: x:=0: seq(f[n], n=0..20); # Zerinvary Lajos, Apr 03 2009 MATHEMATICA With[{nn=20}, CoefficientList[Series[Tanh[x]/(1+x), {x, 0, nn}], x] Range[ 0, nn]!] (* Harvey P. Dale, Jul 18 2013 *) CROSSREFS Sequence in context: A026089 A052835 A009565 * A088335 A066318 A066952 Adjacent sequences:  A009835 A009836 A009837 * A009839 A009840 A009841 KEYWORD sign,easy AUTHOR EXTENSIONS Extended with signs by Olivier Gérard, Mar 15 1997 Prior Mathematica program replaced and definition clarified by Harvey P. Dale, Jul 18 2013 STATUS approved

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Last modified January 16 21:37 EST 2019. Contains 319206 sequences. (Running on oeis4.)