A092469 a(n) = Sum_{i+j+k=n, 0<=i<=j<=k<=n} (n+2j)!/(i! * (3j)! * k!).

1, 1, 13, 91, 1081, 10606, 181189, 2025325, 38378449, 548523856, 10811257051, 176339404099, 3828413138785, 68734868302738, 1590128353317001, 31543123841374681, 768191679788034529, 16494997547298477340

Offset

0,3

Links

Vaclav Kotesovec, Table of n, a(n) for n = 0..500 (terms 0..200 from Seiichi Manyama)

Prog

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

Crossrefs

Cf. A092468.

Sequence in context: A221144 A022578 A090020 * A300779 A275918 A027670

Adjacent sequences: A092466 A092467 A092468 * A092470 A092471 A092472

Keyword

nonn

Author

Benoit Cloitre, Mar 25 2004

Status

approved