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%I #13 Sep 08 2022 08:44:38
%S 0,0,-1,4,-6,8,-90,152,6440,-69984,451080,-4819168,67077648,
%T -533622208,882593712,16010702528,-325947073920,15149145074176,
%U -402497641556352,6097893929134592,-75930618112953600,1338998058465717248,-21267088125132503808
%N Expansion of e.g.f. tanh(log(x+1) - tanh(x)).
%H Vincenzo Librandi, <a href="/A013289/b013289.txt">Table of n, a(n) for n = 0..200</a>
%e -(1/2!)*x^2 + (4/3!)*x^3 - (6/4!)*x^4 + (8/5!)*x^5 - ...
%t Range[0, 25]! CoefficientList[Series[Tanh[Log[x + 1] - Tanh[x]], {x, 0, 25}], x] (* _Vincenzo Librandi_, Aug 03 2018 *)
%o (Magma) m:=30; R<x>:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!(1+Tanh(Log(x+1) - Tanh(x)))); [0] cat [Factorial(n-1)*b[n]: n in [2..m]]; // _Vincenzo Librandi_, Aug 03 2018
%K sign
%O 0,4
%A Patrick Demichel (patrick.demichel(AT)hp.com)
%E a(0)=a(1)=0 inserted and title improved by _Sean A. Irvine_, Aug 03 2018