|
| |
|
|
A012152
|
|
arctanh(tan(tan(x)))=x+6/3!*x^3+176/5!*x^5+12240/7!*x^7...
|
|
0
|
|
|
|
1, 6, 176, 12240, 1561088, 318007808, 94807748608, 38942692972544, 21088169713729536, 14558790290337431552, 12481351528273319821312, 13009249833253480856289280, 16200881782506627598590672896
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
0,2
|
|
|
LINKS
|
Table of n, a(n) for n=0..12.
|
|
|
FORMULA
|
a(n) ~ (2*n)! / (arctan(Pi/4))^(2*n+1). - Vaclav Kotesovec, Feb 05 2015
|
|
|
MATHEMATICA
|
nn = 20; Table[(CoefficientList[Series[ArcTanh[Tan[Tan[x]]], {x, 0, 2*nn+1}], x] * Range[0, 2*nn+1]!)[[n]], {n, 2, 2*nn, 2}] (* Vaclav Kotesovec, Feb 05 2015 *)
|
|
|
CROSSREFS
|
Sequence in context: A024277 A012177 A012227 * A165928 A024278 A062240
Adjacent sequences: A012149 A012150 A012151 * A012153 A012154 A012155
|
|
|
KEYWORD
|
nonn
|
|
|
AUTHOR
|
Patrick Demichel (patrick.demichel(AT)hp.com)
|
|
|
STATUS
|
approved
|
| |
|
|
