A024225 - OEIS

%I #13 Apr 02 2017 14:11:33

%S 0,1,2,-9,-428,-5475,251382,21193459,276227560,-106494482439,

%T -11901572968150,248514536608943,277290379883298492,

%U 34240556133396062229,-5078626013008010061410

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

%F a(n) = A009667(n)/2. [_Martin Ettl_, Nov 08 2012]

%t nn = 30; t = Range[0, nn]! CoefficientList[Series[Tan[Sin[x]]*x/2, {x, 0,nn}], x]; Take[t, {1, nn, 2}] (* _T. D. Noe_, Nov 08 2012 *)

%Y Cf. A009667.

%K sign

%O 0,3

%A _R. H. Hardin_

%E Extended with signs Mar 1997