Moore graph

Named in 1960 by Hoffman and Singleton, after Edward F. Moore, who posed the question of describing and classifying these graphs.

Moore graph (plural Moore graphs)

1. (graph theory) A regular graph of degree d and diameter k whose number of vertices equals the upper bound ${\displaystyle 1+d\sum _{i=0}^{k-1}(d-1)^{i}}$.