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 A335829 #8 Jun 26 2020 09:13:57
%S A335829 2,12,360,5040,113400,29937600,2724321600,14859936000,12504636144000,
%T A335829 2375880867360000,4390627842881280000,605906642317616640000,
%U A335829 8950893579692064000000,74435631008719204224000000,32379499488792853837440000000,8030115873220627751685120000000
%N A335829 Denominators of coefficients in a power series expansion of the distance between two bodies falling freely towards each other along a straight line under the influence of their mutual gravitational attraction.
%C A335829 See A335828 for details.
%H A335829 Amiram Eldar, <a href="/A335829/b335829.txt">Table of n, a(n) for n = 1..238</a>
%t A335829 c[1] = 1/2; c[n_] := c[n] = (2*Sum[(n - k)*(2*n - 2*k - 1)*c[n - k]*c[k], {k, 1, n - 1}] - Sum[(n - m)*(2*n - 2*m - 1)*c[n - m]*c[m - k]*c[k], {m, 2, n - 1}, {k, 1, m - 1}])/(n*(2*n - 1)); Denominator @ Array[c, 16]
%t A335829 (* or *)
%t A335829 Quiet[-Denominator @ CoefficientList[AsymptoticDSolveValue[{y[x]*y'[x]^2 == 2*(1-y[x]), y[0] == 1}, y[x], {x, 0, 25}], x][[3;;-1;;2]]] (* requires Mathematica 11.3+ *)
%Y A335829 Cf. A335828 (numerators).
%K A335829 nonn,frac
%O A335829 1,1
%A A335829 _Amiram Eldar_, Jun 25 2020