A141764 Column 4 of triangle A141760.

1, 1, 5, 36, 336, 3863, 52944, 844777, 15411547, 316888806, 7258887646, 183464090374, 5074934980977, 152584140132667, 4956824851572271, 173086933804868142, 6467223731119047195, 257524741272166890188

Offset

0,3

Links

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

Formula

G.f.: 1/(1-x) = Sum_{n>=0} a(n) * x^n/(1+x)^{(n+3)*(n+4)/2 - 6}.

a(n) = 1 - Sum_{j=0..n-1} a(j) * (-1)^(n-j) * C((j+3)(j+4)/2 + n-j-7, n-j) for n>0, with a(0)=1.

Prog

(PARI) {a(n)=if(n==0, 1, 1 - sum(j=0, n-1, a(j)*(-1)^(n-j)*binomial((j+3)*(j+4)/2-6+n-j-1, n-j)))}

Crossrefs

Cf. A141760, A141761, A141762, A141763.

Sequence in context: A000806 A278990 A127132 * A075744 A277610 A261899

Adjacent sequences: A141761 A141762 A141763 * A141765 A141766 A141767

Keyword

nonn

Author

Paul D. Hanna, Jul 18 2008

Status

approved