A013198 E.g.f.: log(sec(x)+arcsinh(x)) = x-2/3!*x^3+12/4!*x^4-32/5!*x^5+72/6!*x^6...

0, 1, 0, -2, 12, -32, 72, 152, -3808, 48448, -333440, 289408, 26461952, -393649024, 4126861312, -34249082624, -93963415552, 12871254335488, -272828216803328, 2591959365570560, 6130847346393088

Offset

0,4

Links

Table of n, a(n) for n=0..20.

Mathematica

With[{nn=20}, Rest[CoefficientList[Series[Log[Sec[x]+ArcSinh[x]], {x, 0, nn}], x]Range[0, nn]!]] (* Harvey P. Dale, Jun 27 2012 *)

Crossrefs

Sequence in context: A240395 A009331 A154252 * A092345 A212761 A102080

Adjacent sequences: A013195 A013196 A013197 * A013199 A013200 A013201

Keyword

sign

Author

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

Extensions

Definition clarified by Harvey P. Dale, Jun 27 2012

a(0)=0 inserted by Sean A. Irvine, Aug 01 2018

Status

approved