Let G = complete graph on 4 vertices, create the sequence G, L(G), L(L(G)), L(L(L(G))), ... where each graph in this sequence is the line graph of the previous graph; a(n) is number of vertices of the n-th graph in this sequence.

A060202

Let G = complete graph on 4 vertices, create the sequence G, L(G), L(L(G)), L(L(L(G))), ... where each graph in this sequence is the line graph of the previous graph; a(n) is number of vertices of the n-th graph in this sequence.