A024271 E.g.f. tan(x)*tan(sin(x))/2, even powers only.

0, 1, 6, 59, 940, 31637, 2005106, 166100111, 16050083800, 1874971666857, 279670143989598, 53041020901061987, 12139626880904714372, 3219275040968635076157, 979189869389394861709514, 342690421890075448877502135, 137691551060667051544057815472

Offset

0,3

Links

Table of n, a(n) for n=0..16.

Mathematica

With[{nn=40}, Take[CoefficientList[Series[Tan[x] Tan[Sin[x]]/2, {x, 0, nn}], x]Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, May 28 2012 *)

Crossrefs

A009748.

Sequence in context: A024382 A053987 A024270 * A271964 A237576 A229097

Adjacent sequences: A024268 A024269 A024270 * A024272 A024273 A024274

Keyword

nonn

Author

R. H. Hardin

Extensions

Extended and signs tested 03/97.

More terms from and definition clarified by Harvey P. Dale, May 28 2012

Status

approved