

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
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,3


LINKS

Table of n, a(n) for n=0..19.


FORMULA

a(n) ~ (n1)! * (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
Adjacent sequences: A009371 A009372 A009373 * A009375 A009376 A009377


KEYWORD

sign,easy


AUTHOR

R. H. Hardin


EXTENSIONS

Extended with signs by Olivier Gérard, Mar 15 1997


STATUS

approved



