A012667 Expansion of sin(tanh(x)*tan(x)).

2, -8, -159328, -1254489728, -20109957303808, -562928915963168768, -18213125504516311441408, 1487241135313514473061711872

Offset

0,1

Links

Table of n, a(n) for n=0..7.

Formula

G.f.: sin(tanh(x)*tan(x)).

(* [ x^(4n+2) ] *)

Example

sin(tanh(x)*tan(x)) = 2/2!*x^2-8/6!*x^6-159328/10!*x^10...

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Sin[Tanh[x]Tan[x]], {x, 0, nn}], x] Range[0, nn]!, {3, -1, 4}]] (* Harvey P. Dale, Sep 16 2023 *)

Crossrefs

Sequence in context: A081979 A012672 A024340 * A124075 A260548 A019315

Adjacent sequences: A012664 A012665 A012666 * A012668 A012669 A012670

Keyword

sign

Author

Patrick Demichel (patrick.demichel(AT)hp.com)

Extensions

Corrected by and prior Mathematica program replaced by Harvey P. Dale, Sep 16 2023

Status

approved