The Harary graph
is a particular example of a k-connected
graph with
graph vertices having the smallest possible number of
edges. The smallest number of edges possible, as achieved by the Harary graph
, is
, where
is the ceiling function
(Harary 1962; Skiena 1990, p. 179; West 2000, p. 151).
Harary graphs are implemented in the Wolfram Language as HararyGraph[k, n].
When or
is even,
is a circulant graph.
is the complete
graph
(Skiena 1990, p. 180).