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 A130554 #10 Nov 09 2019 15:25:03
%S A130554 1,6,5,140,1260,110,60060,72072,680680,12932920,38798760,11440660,
%T A130554 185910725,5736673800,4621209450,3438179830800,10314539492400,
%U A130554 140744203600,59365905078480,127212653739600,4056670180362800
%N A130554 Denominators of partial sums for a series for 2*Pi*sqrt(3)/9.
%C A130554 Numerators are given in A130553.
%C A130554 For the rationals r(n) := 2*Sum_{j=1..n} 1/(j*binomial(2*j,j)), n >= 1, the A. Comtet reference and a W. Lang link see A130553.
%F A130554 a(n) = denominator(r(n)), n >= 1, with the rationals r(n) defined above.
%o A130554 (PARI) a(n) = denominator(2*sum(j=1, n, 1/(j*binomial(2*j, j)))); \\ _Michel Marcus_, Nov 09 2019
%Y A130554 Cf. A130553 (numerators), A248897 (2*Pi*sqrt(3)/9).
%K A130554 nonn,frac,easy
%O A130554 1,2
%A A130554 _Wolfdieter Lang_, Jul 13 2007