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Expansion of tan(tan(x))*sinh(x).
1

%I #12 Jan 23 2015 14:37:56

%S 0,2,20,518,27432,2405194,312554428,56240197198,13369846932560,

%T 4056020122211730,1528702557462347620,700644649971815625622,

%U 383722595185095053746040,247477546043660240025524954

%N Expansion of tan(tan(x))*sinh(x).

%F a(n) ~ (2*n)! * 8 * sinh(arctan(Pi/2)) / ((4+Pi^2) * arctan(Pi/2)^(2*n+1)). - _Vaclav Kotesovec_, Jan 23 2015

%t Tan[ Tan[ x ] ]*Sinh[ x ] (* Even Part *)

%t nn = 20; Table[(CoefficientList[Series[Sinh[x]*Tan[Tan[x]], {x, 0, 2*nn}], x] * Range[0, 2*nn]!)[[n]], {n, 1, 2*nn+1, 2}] (* _Vaclav Kotesovec_, Jan 23 2015 *)

%K nonn

%O 0,2

%A _R. H. Hardin_

%E Extended and signs tested Mar 15 1997 by _Olivier GĂ©rard_.