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%I #23 Feb 15 2018 15:38:36
%S 1,-3,49,-1859,127297,-13662371,2114110257,-445110767139,
%T 122308548673025,-42491524107649475,18204849127687565745,
%U -9427087716053634833795,5803356448065850202170945,-4188507975000626549209008995,3502566426777342320289454951345
%N E.g.f.: tanh(arcsin(arctan(x))), odd powers only.
%H Vincenzo Librandi, <a href="/A012094/b012094.txt">Table of n, a(n) for n = 0..100</a>
%e tanh(arcsin(arctan(x))) = x-3/3!*x^3+49/5!*x^5-1859/7!*x^7+127297/9!*x^9...
%p a:= n-> (t-> t!*coeff(series(tanh(arcsin(arctan(x))), x, t+1), x, t))(2*n+1):
%p seq(a(n), n=0..17); # _Alois P. Heinz_, Feb 15 2018
%t With[{nn=30},Take[CoefficientList[Series[Tanh[ArcSin[ArcTan[x]]],{x,0,nn}], x]Range[0,nn-1]!,{2,-1,2}]] (* _Harvey P. Dale_, May 09 2012 *)
%K sign
%O 0,2
%A Patrick Demichel (patrick.demichel(AT)hp.com)