|
|
A365150
|
|
G.f. satisfies A(x) = 1 + x*A(x)^2 / (1 - x*A(x))^3.
|
|
4
|
|
|
1, 1, 5, 26, 150, 925, 5967, 39772, 271758, 1893431, 13400897, 96078789, 696333585, 5093266409, 37549674939, 278739057687, 2081637677823, 15628794649931, 117897848681271, 893167062280029, 6792410218680749, 51835002735642287, 396821349652564273
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,3
|
|
LINKS
|
|
|
FORMULA
|
If g.f. satisfies A(x) = ( 1 + x*A(x)^2 / (1 - x*A(x))^s )^t, then a(n) = Sum_{k=0..n} binomial(t*(n+k+1),k) * binomial(n+(s-1)*k-1,n-k)/(n+k+1).
|
|
PROG
|
(PARI) a(n, s=3, t=1) = sum(k=0, n, binomial(t*(n+k+1), k)*binomial(n+(s-1)*k-1, n-k)/(n+k+1));
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|