All minimum C5-saturated graphs
A graph is C5- saturated if it has no five-cycle as a subgraph, but does contain a C5 after the addition of any new edge. Extending our previous result, we prove that the minimum number of edges in a C5-saturated graph on n vertices is sat(n, C5) = ?10(n ? 1)/7? ? 1 for 11?n?14, or n = 16, 18, 20, and is ?10(n ? 1)/7? for all other n?5, and we also prove that the only C5-saturated graphs with sat(n, C5) edges are the graphs described in Section 2.  2011 Wiley Periodicals, Inc. J Graph Theory 67: 9-26, 2011
c5-saturated graphs extremal graphs forbidden subgraphs