login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A009362 Expansion of ln(1+sinh(x)/exp(x)). 2
0, 1, -3, 12, -66, 480, -4368, 47712, -608016, 8855040, -145083648, 2641216512, -52891055616, 1155444326400, -27344999497728, 696933753434112, -19031293222127616, 554336947975618560, -17155693983744196608 (list; graph; refs; listen; history; internal format)
OFFSET

0,3

FORMULA

a(n) = -Sum_{k>0} (-2*k)^n/3^k/k = -(-2)^n*polylog(-n+1, 1/3), n>0. - Vladeta Jovovic (vladeta(AT)eunet.rs), Sep 30 2003

a(n) = -(-1)^n*Sum_{k=0..n-1} 3^k*Sum_{j=0..k} (-1)^j*(k-j)^n*C(n,j) for n>0. a(n) = -(-1)^n*Sum_{k=0..n-1} 3^k*A008292(n-1,k) for n>0, where A008292 are the Eulerian numbers. - Paul D. Hanna (pauldhanna(AT)juno.com), Mar 29 2006

MATHEMATICA

Log[ 1+Sinh[ x ]/Exp[ x ] ]

PROG

(PARI) a(n)=-(-1)^n*sum(k=0, n-1, 3^k*sum(j=0, k, (-1)^j*(k-j)^(n-1)*binomial(n, j))) - Paul D. Hanna (pauldhanna(AT)juno.com), Mar 29 2006

CROSSREFS

Cf. A008292 (Eulerian numbers).

Sequence in context: A199746 A080599 A120575 * A123227 A196556 A107713

Adjacent sequences:  A009359 A009360 A009361 * A009363 A009364 A009365

KEYWORD

sign,easy

AUTHOR

R. H. Hardin (rhhardin(AT)att.net)

EXTENSIONS

Extended with signs Mar 15 1997 by Olivier Gerard.

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified February 12 14:29 EST 2012. Contains 205419 sequences.