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A009374
Expansion of log(1+tan(x))/exp(x).
5
0, 1, -3, 10, -40, 205, -1287, 9714, -85384, 859889, -9751651, 123102098, -1711387808, 25985945453, -427828028695, 7591346835562, -144408464041712, 2931676572255297, -63262735545686819, 1445955290624608506
OFFSET
0,3
FORMULA
a(n) ~ (n-1)! * (-1)^(n+1) * exp(Pi/4) * (4/Pi)^n. - Vaclav Kotesovec, Jan 23 2015
MATHEMATICA
Log[ 1+Tan[ x ] ]/Exp[ x ]
CoefficientList[Series[Log[1 + Tan[x]]/E^x, {x, 0, 20}], x] * Range[0, 20]! (* Vaclav Kotesovec, Jan 23 2015 *)
CROSSREFS
Sequence in context: A030868 A030891 A030911 * A297213 A216386 A256157
KEYWORD
sign,easy
AUTHOR
EXTENSIONS
Extended with signs by Olivier Gérard, Mar 15 1997
STATUS
approved