A174603 a(n) = n!*3^n/Gamma((n+1)/3) *sum_{k=0..floor(n/3)} 3^(-k) *Gamma((n+1)/3-k) / (k!*(n-3*k)!) , where Gamma (Greek capital gamma) is the Gamma-function.

1, 3, 9, 189, 1053, 5103, 88209, 645165, 4048137, 65209779, 563386509, 4202694477, 65731280085, 638202713931, 5411035008297, 83729760898797, 888040122326001, 8324727674858595

Offset

0,2

Links

Table of n, a(n) for n=0..17.

Crossrefs

Sequence in context: A078590 A358704 A061963 * A062228 A196864 A279834

Adjacent sequences: A174600 A174601 A174602 * A174604 A174605 A174606

Keyword

nonn

Author

Katarzyna Gorska and Karol A. Penson, Mar 23 2010

Status

approved