A009363 Expansion of log(1+tan(log(1+x))).

0, 1, -2, 9, -55, 434, -4180, 47590, -625770, 9339880, -156097760, 2889491800, -58706203400, 1299203207600, -31115627649600, 801958361812400, -22134642846706000, 651438145653776000, -20365743882600064000

Offset

0,3

Links

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

Formula

a(n) ~ (n-1)! * (-1)^(n+1) / (1-exp(-Pi/4))^n. - Vaclav Kotesovec, Jan 23 2015

Mathematica

With[{nn=20}, CoefficientList[Series[Log[1+Tan[Log[1+x]]], {x, 0, nn}], x]Range[0, nn]!] (* Harvey P. Dale, Sep 28 2011 *)

Crossrefs

Sequence in context: A355281 A036074 A231172 * A069564 A109366 A303914

Adjacent sequences: A009360 A009361 A009362 * A009364 A009365 A009366

Keyword

sign,easy

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Status

approved