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The PoussinGraph() command returns the Poussin graph, a planar undirected graph with 15 vertices and 39 edges.

The Poussin graph was discovered by Charles Jean de la Vallée-Poussin as a counterexample to an incorrect proof of the four color theorem.

$\mathrm{with}\left(\mathrm{GraphTheory}\right)\:$

$\mathrm{with}\left(\mathrm{SpecialGraphs}\right)\:$

$G≔\mathrm{PoussinGraph}\left(\right)$

$G≔\mathrm{Graph\; 1:\; an\; undirected\; graph\; with\; 15\; vertices\; and\; 39\; edges}$

$\mathrm{IsPlanar}\left(G\right)$

$\mathrm{true}$

$\mathrm{DrawGraph}\left(G\right)$

"Poussin graph", Wikipedia. http://en.wikipedia.org/wiki/Poussin_graph

The GraphTheory[SpecialGraphs][PoussinGraph] command was introduced in Maple 2018.

For more information on Maple 2018 changes, see Updates in Maple 2018 .