A009485 Expansion of e.g.f. sin(sin(x)/cosh(x)), odd powers only.

1, -5, 77, -2641, 149529, -12183613, 1342074021, -192192501897, 34713417890609, -7713202738776565, 2065351603144405245, -655189775541151687489, 242766537537541761422153, -103817685952332598159305517

Offset

0,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..100

Formula

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

Maple

a:= n-> (2*n+1)!*coeff(series(sin(sin(x)/cosh(x)), x, 2*n+2), x, 2*n+1):
seq(a(n), n=0..20);  # Alois P. Heinz, Feb 09 2014

Mathematica

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 *)

Prog

(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

Crossrefs

Sequence in context: A287041 A360351 A318236 * A188455 A015056 A326870

Adjacent sequences: A009482 A009483 A009484 * A009486 A009487 A009488

Keyword

sign

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Prior Mathematica program deleted by Harvey P. Dale, Aug 17 2013

Status

approved