%N Number of vertices in the iterated clique graphs of the 1-skeleton of Plato's octahedron.
%C The octahedron was the first known example of a k-divergent graph.
%H Miguel A. Pizaña, <a href="https://doi.org/10.1016/S0012-365X(02)00502-2">The icosahedron is clique divergent</a>, Discrete Mathematics, 262 (Feb. 2003), pp. 229-239.
%H YAGS, <a href="http://xamanek.izt.uam.mx/yags/">YAGS - Yet Another Graph System</a>
%e By definition, the zeroth iterated clique graph of a graph G is equal to G itself; since the octahedron has 6 vertices, a(0)=6.
%e The first iterated clique graph of the octahedron has 8 vertices; hence, a(1)=8.
%o (YAGS) K:=CliqueGraph;; g:=Octahedron;; kg:=K(g);; Order(kg);
%o # It outputs the number of vertices in the first iterated
%o # clique graph of the octahedron.
%Y Cf. A299028, A063723, A053016.
%A _José Hernández_, Feb 01 2018