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 A055342 #11 Mar 30 2012 17:37:11 %S A055342 1,4,16,46,118,260,527,985,1741,2918,4701,7299,11004,16142,23148, %T A055342 32502,44823,60786,81238,107098,139492,179632,228979,289097,361841, %U A055342 449188,553453,677093,822954,994044,1193814,1425902,1694445,2003790 %N A055342 Number of mobiles (circular rooted trees) with n nodes and 4 leaves. %H A055342 <a href="/index/Mo#mobiles">Index entries for sequences related to mobiles</a> %F A055342 Conjecture: G.f. x^5*( -1-x-5*x^2-6*x^3-9*x^4-5*x^5-2*x^6-2*x^7+x^9 ) / ( (x^2+1)*(1+x+x^2) *(1+x)^3 *(x-1)^7 ). - R. J. Mathar, Sep 18 2011 %Y A055342 Column 4 of A055340. %K A055342 nonn %O A055342 5,2 %A A055342 _Christian G. Bower_, May 14 2000