The graph is the biconnected
graph on seven nodes and eight edges
illustrated above. It has chromatic polynomial
and chromatic number .
The puz-graph of a finite simple biconnected
graph
that is not polygonal always has two connected
components if
is bipartite; otherwise (with the exception of
),
is connected. Surprisingly,
the puz-graph of the
graph is the sole exception, having six connected
components instead of a single connected component.