A092466 a(n) = Sum_{i+j+k=n, 0<=j<=i<=k<=n} (n+k)!/(i! * j! * (2*k)!).

1, 1, 3, 16, 41, 166, 777, 2472, 9781, 44506, 150953, 597334, 2661881, 9337511, 37044451, 162468924, 582650861, 2315651686, 10035973071, 36558456606, 145470310301, 624753156831, 2302445024223, 9169599427426, 39098606269531

Offset

0,3

Links

Vaclav Kotesovec, Table of n, a(n) for n = 0..1000 (terms 0..200 from Seiichi Manyama)

Vaclav Kotesovec, Plot of a(n+1)/a(n) for n = 1..999

Prog

(PARI) a(n)=sum(i=0, n, sum(j=0, i, sum(k=0, j, if(i+j+k-n, 0, (n+k)!/i!/j!/(2*k)!))))

Crossrefs

Cf. A092465.

Sequence in context: A081270 A271374 A147874 * A374296 A152618 A296947

Adjacent sequences: A092463 A092464 A092465 * A092467 A092468 A092469

Keyword

nonn

Author

Benoit Cloitre, Mar 25 2004

Status

approved