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

Author

Paul D. Hanna, Aug 06 2012

Keywords

• nonn

Comments

Column 3 of triangle A215241.

Examples

			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 +...
		

Crossrefs

Cf. A215241, A177447, A215242, A133316.

Programs

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)", "))