|
Search: id:A009775
|
|
|
| A009775 |
|
Expansion of tanh(ln(1+x)). |
|
+0
6
|
|
| 0, 1, -1, 0, 6, -30, 90, 0, -2520, 22680, -113400, 0, 7484400, -97297200, 681080400, 0, -81729648000, 1389404016000, -12504636144000, 0, 2375880867360000, -49893498214560000, 548828480360160000, 0, -151476660579404160000
(list; graph; listen)
|
|
|
OFFSET
|
0,5
|
|
|
FORMULA
|
a(0) = 0, a(4n+3) = 0, a(n) = (-1)^[n == 2, 5, 8 mod 8] * n!/2^floor(n/2). - Ralf Stephan (ralf(AT)ark.in-berlin.de), Mar 06 2004
|
|
MATHEMATICA
|
Tanh[ Log[ 1+x ] ]
|
|
CROSSREFS
|
Cf. A052277, A007019, A046979, A007415, A007452, A092820.
Sequence in context: A152788 A055112 A094143 this_sequence A119536 A107394 A033487
Adjacent sequences: A009772 A009773 A009774 this_sequence A009776 A009777 A009778
|
|
KEYWORD
|
sign,easy
|
|
AUTHOR
|
R. H. Hardin (rhhardin(AT)att.net)
|
|
EXTENSIONS
|
Extended with signs Mar 15 1997 by Olivier Gerard.
|
|
|
Search completed in 0.002 seconds
|
