The density of a simple graph is defined as the edge count m divided by the possible number of edges in the graph, i.e., ρ(G) | = | ( left bracketing bar E(G) right bracketing bar )/( left bracketing bar V(G) right bracketing bar 2) | = | (2m)/(n(n - 1)), where m = left bracketing bar E(G) right bracketing bar is the edge count of G, n = left bracketing bar V(G) right bracketing bar the vertex count, and (a b) is a binomial coefficient.

edge count | maximally dense unit-distance graph | vertex count