OFFSET
0,3
FORMULA
a(n) ~ (n-1)! * (-1)^(n+1) / (arctan(1-exp(-1))^n). - Vaclav Kotesovec, Jan 22 2015
MATHEMATICA
Log[ 1+Log[ 1+Tan[ x ] ] ]
CoefficientList[Series[Log[1 + Log[1 + Tan[x]]], {x, 0, 20}], x] * Range[0, 20]! (* Vaclav Kotesovec, Jan 22 2015 *)
CROSSREFS
KEYWORD
sign,easy
AUTHOR
EXTENSIONS
Extended with signs by Olivier Gérard, Mar 15 1997
STATUS
approved