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%I #10 Jun 22 2015 22:38:07
%S 0,1,-1,2,-6,16,0,-792,13776,-200552,2855880,-41436352,620388912,
%T -9606956592,153409074000,-2508503487232,41503122145920,
%U -680444083117184,10600133081473152,-140189781816392448,819083424632851200
%N Expansion of tanh(tan(log(1+x))).
%t Tanh[ Tan[ Log[ 1+x ] ] ]
%K sign,easy
%O 0,4
%A _R. H. Hardin_
%E Extended with signs by _Olivier Gérard_, Mar 15 1997