BrouwerHaemersGraph - Maple Help

GraphTheory[SpecialGraphs]

 BrouwerHaemersGraph
 construct Brouwer-Haemers graph

 Calling Sequence BrouwerHaemersGraph()

Description

 • The BrouwerHaemersGraph command creates the Brouwer-Haemers graph.
 • The Brouwer-Haemers graph is a strongly regular graph with 81 vertices and 810 edges.

Examples

 > $\mathrm{with}\left(\mathrm{GraphTheory}\right):$
 > $\mathrm{with}\left(\mathrm{SpecialGraphs}\right):$
 > $\mathrm{BH}≔\mathrm{BrouwerHaemersGraph}\left(\right)$
 ${\mathrm{BH}}{≔}{\mathrm{Graph 1: an undirected unweighted graph with 81 vertices and 810 edge\left(s\right)}}$ (1)
 > $\mathrm{IsStronglyRegular}\left(\mathrm{BH},'\mathrm{parameters}'\right)$
 ${\mathrm{true}}{,}\left[{20}{,}{1}{,}{6}\right]$ (2)
 > $\mathrm{ChromaticNumber}\left(\mathrm{BH}\right)$
 ${7}$ (3)

References

 "Brouwer-Haemers graph", Wikipedia. http://en.wikipedia.org/wiki/Brouwer-Haemers_graph

Compatibility

 • The GraphTheory[SpecialGraphs][BrouwerHaemersGraph] command was introduced in Maple 2020.