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 A378156 #8 Nov 18 2024 09:44:57
%S A378156 1,8,72,720,7728,87104,1017184,12200640,149429504,1861059328,
%T A378156 23498407680,300110580224,3870135336192,50323754919936,
%U A378156 659085377250816,8686436702866432,115120162870534144,1533214282017157120,20510220228874399744,275462154992599851008,3712900128220039372800
%N A378156 G.f. A(x) satisfies A(x) = ( 1 + x * A(x)^(1/2) * (1 + A(x)^(1/2)) )^4.
%F A378156 G.f.: B(x)^4 where B(x) is the g.f. of A219534.
%F A378156 a(n) = 2 * Sum_{k=0..n} binomial(n,k) * binomial(2*n+2*k+4,n)/(n+k+2).
%o A378156 (PARI) a(n, r=4, t=2, u=2) = r*sum(k=0, n, binomial(n, k)*binomial(t*n+u*k+r, n)/(t*n+u*k+r));
%Y A378156 Cf. A219534, A371693, A378155.
%K A378156 nonn
%O A378156 0,2
%A A378156 _Seiichi Manyama_, Nov 18 2024