A009485 - OEIS

%I #25 Feb 09 2014 12:19:10

%S 1,-5,77,-2641,149529,-12183613,1342074021,-192192501897,

%T 34713417890609,-7713202738776565,2065351603144405245,

%U -655189775541151687489,242766537537541761422153,-103817685952332598159305517

%N Expansion of e.g.f. sin(sin(x)/cosh(x)), odd powers only.

%H Vincenzo Librandi, <a href="/A009485/b009485.txt">Table of n, a(n) for n = 0..100</a>

%F a(n) = (2n+1)! * [x^(2n+1)] sin(sin(x)/cosh(x)). - _Alois P. Heinz_, Feb 09 2014

%p a:= n-> (2*n+1)!*coeff(series(sin(sin(x)/cosh(x)), x, 2*n+2), x, 2*n+1):

%p seq(a(n), n=0..20);  # _Alois P. Heinz_, Feb 09 2014

%t With[{nn=30},Take[CoefficientList[Series[Sin[Sin[x]/Cosh[x]],{x,0,nn}],x] Range[0,nn-1]!,{2,-1,2}]] (* _Harvey P. Dale_, Aug 17 2013 *)

%o (PARI) my(x='x+O('x^39));vector(1/2*#v=Vec(sin(sin(x)/cosh(x))),n,v[2*n+1]*(2*n+1)!) \\ _M. F. Hasler_, Feb 09 2014

%K sign

%O 0,2

%A _R. H. Hardin_

%E Extended with signs by _Olivier Gérard_, Mar 15 1997

%E Prior Mathematica program deleted by _Harvey P. Dale_, Aug 17 2013