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 A058855 #11 Sep 13 2015 20:58:42
%S A058855 1,1,4,8,22,52,142,362,973,2574,6935,18643,50573,137401,375306,
%T A058855 1027898,2825831,7790055,21539352,59706865,165921896,462127857,
%U A058855 1289901083,3607567539,10108555623,28374358327,79777757405,224653284863
%N A058855 Number of 6-bead necklaces where each bead is an unlabeled rooted tree, by total number of nodes.
%C A058855 The 6 beads are just placeholders; only tree nodes are counted.
%F A058855 Plug g.f. for A000081, 1+x+x^2+2*x^3+4*x^4+ ... into cycle index for dihedral group D_12.
%F A058855 Cycle index for D_12 is 1/12*Z[1]^6+1/6*Z[6]+1/4*Z[1]^2*Z[2]^2+1/6*Z[3]^2+1/3*Z[2]^3.
%e A058855 a(3) = 8 since the 3 nodes may be arranged around the necklace as 111000, 110100, 101010, 210000, 201000, 200100, 300000 and in the latter arrangement there are two possible trees that can be used because A000081(3)=2.
%t A058855 nn=20;f[x_]:=Sum[a[n]x^n,{n,0,nn}];sol=SolveAlways[0==Series[f[x]-x Product[1/(1-x^i)^a[i],{i,1,nn}],{x,0,nn}],x];t=Prepend[Table[a[n],{n,1,nn}]/.sol//Flatten,1];Drop[CoefficientList[Series[CycleIndex[DihedralGroup[6],s]/.Table[s[i]->Sum[t[[k]]x^((k-1) i),{k,1,nn-1}],{i,1,6}],{x,0,nn}],x],-2] (* _Geoffrey Critzer_, Feb 22 2013 *)
%K A058855 nonn
%O A058855 0,3
%A A058855 _N. J. A. Sloane_, Jan 18 2001