OFFSET
0,4
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
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