A012777 Expansion of e.g.f. arctanh(sec(x) * log(x+1)).

0, 1, -1, 7, -24, 223, -1635, 19409, -221592, 3270325, -50128965, 898512371, -17140184688, 364328185843, -8275583884295, 204221077642685, -5369189766162960, 151121003206989833, -4508710182336979593

Offset

0,4

Links

Table of n, a(n) for n=0..18.

Example

x - 1/2!*x^2 + 7/3!*x^3 - 24/4!*x^4 + 223/5!*x^5 ...

Mathematica

Range[0, 20]! CoefficientList[ Series[ArcTanh[Sec[x] Log[x + 1]], {x, 0, 20}], x] (* Robert G. Wilson v, Jul 24 2018 *)

Prog

(PARI) x = 'x + O('x^30); concat(0, Vec(serlaplace(atanh(log(x+1)/cos(x))))) \\ Michel Marcus, Jul 27 2018

Crossrefs

Sequence in context: A203117 A197791 A009652 * A074783 A286742 A322563

Adjacent sequences: A012774 A012775 A012776 * A012778 A012779 A012780

Keyword

sign

Author

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

Extensions

a(0) inserted and title improved by Sean A. Irvine, Jul 24 2018

Status

approved