A009728 Expansion of tan(x)*cos(sinh(x)).

1, -1, -19, -253, -5447, -225721, -14615899, -1266041845, -140130487823, -19419956236657, -3304321034706211, -677542297845085165, -164755897732586842199, -46874838119958767992105

Offset

0,3

Links

Table of n, a(n) for n=0..13.

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Tan[x]*Cos[Sinh[x]], {x, 0, nn}], x] Range[0, nn-1]!, {2, -1, 2}]]

Crossrefs

Sequence in context: A017952 A055433 A185425 * A027532 A021394 A016316

Adjacent sequences: A009725 A009726 A009727 * A009729 A009730 A009731

Keyword

sign

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Previous Mathematica program replaced by Harvey P. Dale, Jan 17 2026

Status

approved