A009429 E.g.f. log(1+x)/cos(x).

0, 1, -1, 5, -12, 69, -285, 2001, -12208, 104073, -854865, 8723549, -90552396, 1088372557, -13647385661, 190057979177, -2787246189120, 44285819490065, -742019231348865, 13267464006201781, -249642268776311020

Offset: 0

Author

R. H. Hardin

Keywords

• sign
• easy

Examples

			log(1+x)/cos(x) = 0 + x - 1/2*x^2 + 5/6*x^3 - 1/2*x^4 + 23/40*x^5 -+ ...
		

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..200

Programs

Mathematica

With[{nn=30},CoefficientList[Series[Log[1+x]/Cos[x],{x,0,nn}], x] Range[0,nn]!] (* Harvey P. Dale, Jan 26 2013 *)

Formula

a(n) ~ (n-1)! * (-1)^(n+1) / cos(1). - Vaclav Kotesovec, Jan 23 2015

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997