%I #11 Dec 01 2020 13:33:47

%S 0,1,6,-49,-8484,-511379,6769026,9445602011,1884673497336,

%T 61550034487321,-126825694957538754,-61388922632885893849,

%U -9399026972435828464044,9252373566488286511114501,9573652356256569791096427066

%N Expansion of tanh(tan(x)*sinh(x))/2.

%t With[{nn=30},Take[CoefficientList[Series[Tanh[Tan[x]*Sinh[x]]/2,{x,0,nn}],x] Range[0,nn]!,{1,-1,2}]] (* _Harvey P. Dale_, Dec 01 2020 *)

%Y Cf. A009816.

%K sign

%O 0,3

%A _R. H. Hardin_

%E Extended with signs Mar 1997

%E Previous Mathematica program replaced by _Harvey P. Dale_, Dec 01 2020