login
A141763
Column 3 of triangle A141760.
4
1, 1, 4, 23, 175, 1678, 19579, 270683, 4342447, 79498622, 1638471038, 37592670383, 951214496814, 26333793485772, 792232525678756, 25747819699179668, 899388184082559576, 33613386298645020835, 1338749843351681925409
OFFSET
0,3
FORMULA
G.f.: 1/(1-x) = Sum_{n>=0} a(n) * x^n/(1+x)^{(n+2)*(n+3)/2 - 3}.
a(n) = 1 - Sum_{j=0..n-1} a(j) * (-1)^(n-j) * C((j+2)(j+3)/2 + n-j-4, 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+2)*(j+3)/2-3+n-j-1, n-j)))}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jul 18 2008
STATUS
approved