OFFSET
0,4
REFERENCES
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
FORMULA
a(n) ~ n! / (exp(Pi/2) * (exp(-Pi/2)-1)^(n+1)). - Vaclav Kotesovec, Feb 16 2015
MATHEMATICA
With[{nn=20}, CoefficientList[Series[Tan[Log[1+x]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, May 28 2013 *)
CROSSREFS
KEYWORD
sign
AUTHOR
STATUS
approved