A012632 sec(arcsinh(x)*arctan(x))=1+12/4!*x^4-360/6!*x^6+26768/8!*x^8...

1, 0, 12, -360, 26768, -3003840, 500757312, -114797434752, 34719912016128, -13385737151096832, 6408112715151793152, -3729311544255904696320, 2592887206723575200256000, -2122643658026530680956928000

Offset

0,3

Links

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

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Sec[ArcSinh[x]ArcTan[x]], {x, 0, nn}], x] Range[ 0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Nov 08 2022 *)

Crossrefs

Sequence in context: A012552 A012385 A012430 * A081791 A166183 A218310

Adjacent sequences: A012629 A012630 A012631 * A012633 A012634 A012635

Keyword

sign

Author

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

Status

approved