MarkstroemGraph - Maple Help
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GraphTheory[SpecialGraphs]

 MarkstroemGraph
 construct Markstroem graph

 Calling Sequence MarkstroemGraph()

Description

 • The MarkstroemGraph() command returns the Markström graph, a planar undirected graph with 15 vertices and 39 edges.
 • The Markstroem graph was discovered by Klas Markström as a counterexample to the open Erdős-Gyárfás conjecture.

Examples

 > $\mathrm{with}\left(\mathrm{GraphTheory}\right):$
 > $\mathrm{with}\left(\mathrm{SpecialGraphs}\right):$
 > $G≔\mathrm{MarkstroemGraph}\left(\right)$
 ${G}{≔}{\mathrm{Graph 1: an undirected graph with 24 vertices and 36 edge\left(s\right)}}$ (1)
 > $\mathrm{IsPlanar}\left(G\right)$
 ${\mathrm{true}}$ (2)
 > $\mathrm{DrawGraph}\left(G,\mathrm{style}=\mathrm{planar}\right)$

References

 "Markstroem graph", Wikipedia. http://en.wikipedia.org/wiki/Erdős–Gyárfás conjecture

Compatibility

 • The GraphTheory[SpecialGraphs][MarkstroemGraph] command was introduced in Maple 2021.
 • For more information on Maple 2021 changes, see Updates in Maple 2021.