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 A371483 #15 Mar 25 2024 12:06:40
%S A371483 1,3,18,124,933,7446,61943,531348,4666425,41751325,379230711,
%T A371483 3487769871,32414437521,303950138604,2872137458010,27322233357964,
%U A371483 261446381792670,2514851398148595,24303030755342128,235841264063844258,2297278004837062317
%N A371483 G.f. A(x) satisfies A(x) = 1 / (1 - x*A(x) / (1-x))^3.
%F A371483 a(n) = Sum_{k=0..n} binomial(n-1,n-k) * binomial(4*k+2,k)/(k+1).
%F A371483 G.f.: A(x) = B(x/(1-x)), where B(x) = (1/x) * Series_Reversion( x*(1-x)^3 ).
%F A371483 G.f.: A(x) = B(x)^3 where B(x) is the g.f. of A349331.
%o A371483 (PARI) a(n) = sum(k=0, n, binomial(n-1, n-k)*binomial(4*k+2, k)/(k+1));
%Y A371483 Cf. A002212, A270386, A371486.
%Y A371483 Cf. A006632, A349331.
%K A371483 nonn
%O A371483 0,2
%A A371483 _Seiichi Manyama_, Mar 25 2024