This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A215243 #6 Oct 20 2024 18:37:03
%S A215243 1,9,99,1416,25650,569772,15099042,466865280,16545757617,662459717350,
%T A215243 29611195466373,1463138718427008,79255793863426950,
%U A215243 4673128560507694980,298096897542679853190,20462949699720864598464,1504570012129788012314910,118004419030927157257862025
%N A215243 G.f.: 1 = Sum_{n>=0} a(n)*x^n/(1+x)^((n+3)^2).
%C A215243 Column 3 of triangle A215241.
%e A215243 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 +...
%o A215243 (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))}
%o A215243 for(n=0,21,print1(a(n)", "))
%Y A215243 Cf. A215241, A177447, A215242, A133316.
%K A215243 nonn
%O A215243 0,2
%A A215243 _Paul D. Hanna_, Aug 06 2012