%I A012680
%S A012680 2,16,80,14464,1682432,76011520,26175092736,10889734127616,
%T A012680 1790915255599104,628448342217064448,708415309969044275200,
%U A012680 277815404352915818676224,89144743290434384702734336
%V A012680 2,-16,80,14464,-1682432,76011520,26175092736,-10889734127616,
%W A012680 1790915255599104,628448342217064448,-708415309969044275200,
%X A012680 277815404352915818676224,89144743290434384702734336
%N A012680 arctan(tanh(x)*atan(x))=2/2!*x^2-16/4!*x^4+80/6!*x^6+14464/8!*x^8...
%Y A012680 Sequence in context: A034581 A028336 A045905 this_sequence A012684 A053587 
               A052346
%Y A012680 Adjacent sequences: A012677 A012678 A012679 this_sequence A012681 A012682 
               A012683
%K A012680 sign
%O A012680 0,1
%A A012680 Patrick Demichel (dml(AT)hpfrcu03.france.hp.com)