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 A055350 #15 Mar 14 2022 10:13:15
%S A055350 8,220,4200,71400,1176000,19474560,330220800,5787936000,105380352000,
%T A055350 1997835840000,39477236198400,813155511168000,17453093898240000,
%U A055350 390070546145280000,9070029416448000000,219204470936715264000
%N A055350 Number of labeled mobiles (circular rooted trees) with n nodes and 3 leaves.
%H A055350 Georg Fischer, <a href="/A055350/b055350.txt">Table of n, a(n) for n = 4..250</a>
%H A055350 <a href="/index/Mo#mobiles">Index entries for sequences related to mobiles</a>
%t A055350 m = 20;
%t A055350 L[x_] = Log[1-x] + O[x]^m // Normal;
%t A055350 A[_] = 0;
%t A055350 Do[A[x_] = x y - x L[A[x]] + O[x]^k // Normal // Expand, {k, m}];
%t A055350 Drop[(SeriesCoefficient[#, {y, 0, 3}]& /@ CoefficientList[A[x], x]) * Range[0, m-1]!, 4] (* _Jean-François Alcover_, Nov 01 2019 *)
%Y A055350 Column 3 of A055349.
%K A055350 nonn
%O A055350 4,1
%A A055350 _Christian G. Bower_, May 15 2000