A379172 G.f. A(x) satisfies A(x) = (1 + x*A(x)^3)/(1 - x*A(x))^3.

1, 4, 33, 358, 4445, 59745, 846023, 12430941, 187753479, 2896929975, 45465112431, 723520554096, 11647721390271, 189352106241567, 3104046096391902, 51254005259550753, 851674902290491936, 14231191062537888864, 238978853442142491358, 4030889937027642017872

Offset

0,2

Links

Table of n, a(n) for n=0..19.

Formula

a(n) = Sum_{k=0..n} binomial(n+2*k+1,k) * binomial(4*n+5*k+2,n-k)/(n+2*k+1).

Prog

(PARI) a(n) = sum(k=0, n, binomial(n+2*k+1, k)*binomial(4*n+5*k+2, n-k)/(n+2*k+1));

Crossrefs

Cf. A365764, A369215, A379171.

Sequence in context: A347749 A362604 A075132 * A303919 A364439 A208961

Adjacent sequences: A379169 A379170 A379171 * A379173 A379174 A379175

Keyword

nonn

Author

Seiichi Manyama, Dec 17 2024

Status

approved