A009408 Expansion of log(1+x)*cos(tan(x)).

0, 1, -1, -1, 0, -31, 75, -953, 3976, -41631, 255375, -2595825, 21904344, -229744191, 2548875147, -28954555113, 403320390960, -5182050779583, 86114063275263, -1283638256263905, 24297343149251280, -420632032451656671

Offset

0,6

Links

Table of n, a(n) for n=0..21.

Formula

a(n) ~ (n-1)! * (-1)^(n+1) * cos(tan(1)). - Vaclav Kotesovec, Jan 24 2015

Mathematica

With[{nn=30}, CoefficientList[Series[Log[1+x]Cos[Tan[x]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Mar 11 2012 *)

Crossrefs

Sequence in context: A130468 A068917 A317053 * A165615 A142408 A246929

Adjacent sequences: A009405 A009406 A009407 * A009409 A009410 A009411

Keyword

sign,easy

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Status

approved