A009316 Expansion of log(1+log(1+x))/cos(x).

0, 1, -2, 10, -47, 323, -2509, 24022, -262884, 3312757, -46812246, 736778634, -12755932287, 241166285111, -4941674443133, 109108249437782, -2582086472552784, 65202893342750121, -1749904916594467218

Offset

0,3

Links

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

Formula

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

Mathematica

Log[ 1+Log[ 1+x ] ]/Cos[ x ]
CoefficientList[Series[Log[1 + Log[1 + x]]*Sec[x], {x, 0, 20}], x] * Range[0, 20]! (* Vaclav Kotesovec, Jan 23 2015 *)

Crossrefs

Sequence in context: A242638 A058149 A009314 * A116194 A054138 A192696

Adjacent sequences: A009313 A009314 A009315 * A009317 A009318 A009319

Keyword

sign,easy

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Status

approved