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 A382650 #8 Apr 02 2025 09:44:35
%S A382650 1,3,24,100,471,2043,8422,34818,137649,543655,2096508,8031948,
%T A382650 30355155,113929497,423562614,1565841650,5745557853,20989365057,
%U A382650 76206968356,275721399480,992423144247,3562075121911,12728422443654,45379998032202,161158522838105,571293893581389
%N A382650 Expansion of 1/(1 - x*(1 + 4*x)^(3/2))^3.
%C A382650 a(100) is negative.
%F A382650 a(n) = Sum_{k=0..n} 4^(n-k) * binomial(k+2,2) * binomial(3*k/2,n-k).
%o A382650 (PARI) a(n) = sum(k=0, n, 4^(n-k)*binomial(k+2, 2)*binomial(3*k/2, n-k));
%Y A382650 Cf. A382536, A382649.
%K A382650 sign,easy
%O A382650 0,2
%A A382650 _Seiichi Manyama_, Apr 02 2025