A013207 Expansion of e.g.f.: log(sech(x)+arcsinh(x))=x-2/2!*x^2+4/3!*x^3-12/4!*x^4+68/5!*x^5...

0, 1, -2, 4, -12, 68, -440, 3064, -26208, 265936, -2945152, 35730176, -485182720, 7235106240, -115677206528, 1984468240000, -36707903762432, 725871298851072, -15190637885095936, 336136505074527232

Offset

0,3

Links

Table of n, a(n) for n=0..19.

Mathematica

With[{nn=20}, CoefficientList[Series[Log[Sech[x]+ArcSinh[x]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Mar 22 2018 *)

Crossrefs

Sequence in context: A217716 A129824 A266463 * A172165 A078919 A372994

Adjacent sequences: A013204 A013205 A013206 * A013208 A013209 A013210

Keyword

sign

Author

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

Extensions

Zero prepended and definition clarified by Harvey P. Dale, Mar 22 2018

Status

approved