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 A055351 #14 Mar 14 2022 07:26:04
%S A055351 30,1500,47250,1234800,29635200,685843200,15717240000,362244960000,
%T A055351 8476532064000,202580554176000,4963223577312000,124948285862400000,
%U A055351 3236755595673600000,86346680044584960000,2372991796225290240000
%N A055351 Number of labeled mobiles (circular rooted trees) with n nodes and 4 leaves.
%H A055351 Georg Fischer, <a href="/A055351/b055351.txt">Table of n, a(n) for n = 5..250</a>
%H A055351 <a href="/index/Mo#mobiles">Index entries for sequences related to mobiles</a>
%t A055351 m = 20; L[x_] = Log[1 - x] + O[x]^m // Normal; A[_] = 0;
%t A055351 Do[A[x_] = x y - x L[A[x]] + O[x]^k // Normal // Expand, {k, m}];
%t A055351 Drop[(SeriesCoefficient[#, {y, 0, 4}] & /@ CoefficientList[A[x], x]) * Range[0, m - 1]!, 5] (* _Jean-François Alcover_, Nov 01 2019 *)
%Y A055351 Column 4 of A055349.
%K A055351 nonn
%O A055351 5,1
%A A055351 _Christian G. Bower_, May 15 2000