A215243 G.f.: 1 = Sum_{n>=0} a(n)*x^n/(1+x)^((n+3)^2).

1, 9, 99, 1416, 25650, 569772, 15099042, 466865280, 16545757617, 662459717350, 29611195466373, 1463138718427008, 79255793863426950, 4673128560507694980, 298096897542679853190, 20462949699720864598464, 1504570012129788012314910, 118004419030927157257862025

Offset

0,2

Comments

Column 3 of triangle A215241.

Links

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

Example

G.f.: 1 = 1/(1+x)^9 + 9*x/(1+x)^16 + 99*x^2/(1+x)^25 + 1416*x^3/(1+x)^36 + 25650*x^4/(1+x)^49 +...

Prog

(PARI) {a(n)=if(n==0, 1, polcoeff(1-sum(k=0, n-1, a(k)*x^k/(1+x+x*O(x^n))^((k+3)^2)), n))}
for(n=0, 21, print1(a(n)", "))

Crossrefs

Cf. A215241, A177447, A215242, A133316.

Sequence in context: A051581 A356100 A080291 * A113395 A070068 A068668

Adjacent sequences: A215240 A215241 A215242 * A215244 A215245 A215246

Keyword

nonn

Author

Paul D. Hanna, Aug 06 2012

Status

approved