login
The OEIS is supported by
the many generous donors to the OEIS Foundation
.
Hints
(Greetings from
The On-Line Encyclopedia of Integer Sequences
!)
A174636
Integral_{x=0..infinity} (x + x^2 + x^3)^n exp(-x).
0
1, 9, 1046, 519918, 681617304, 1853340127320, 9049964145536880, 72083636411763075120, 874164613833481641471360, 15325066482283901592487889280, 372998446683217113984893861356800
(
list
;
graph
;
refs
;
listen
;
history
;
text
;
internal format
)
OFFSET
0,2
LINKS
Table of n, a(n) for n=0..10.
MATHEMATICA
Trinomial[n_, k_] := If[k == 0, 1, Coefficient[(1 + x + x^2)^n, x^k]]; a[n_] := Sum[Trinomial[n, k](n + k)!, {k, 0, 2n}]; Table[a[n], {n, 0, 20}]
CROSSREFS
Sequence in context:
A172944
A277829
A286396
*
A054344
A048912
A036411
Adjacent sequences:
A174633
A174634
A174635
*
A174637
A174638
A174639
KEYWORD
nonn
AUTHOR
Emanuele Munarini
, Jan 25 2011
STATUS
approved
Lookup
|
Welcome
|
Wiki
|
Register
|
Music
|
Plot 2
|
Demos
|
Index
|
Browse
|
More
|
WebCam
Contribute new seq. or comment
|
Format
|
Style Sheet
|
Transforms
|
Superseeker
|
Recents
The OEIS Community
| Maintained by
The OEIS Foundation Inc.
License Agreements, Terms of Use, Privacy Policy.
.
Last modified April 24 18:17 EDT 2024. Contains 371962 sequences. (Running on oeis4.)