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Kittell graph

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Kittell graph
The Kittell graph
Vertices23
Edges63
Radius3
Diameter4
Girth3
Table of graphs and parameters

In the mathematical field of graph theory, the Kittell graph is a planar graph with 23 vertices and 63 edges. Its unique planar embedding has 42 triangular faces.[1] The Kittell graph is named after Irving Kittell, who used it as a counterexample to Alfred Kempe's flawed proof of the four-color theorem.[2] Simpler counterexamples include the Errera graph and Poussin graph (both published earlier than Kittell) and the Fritsch graph and Soifer graph.

References

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  1. ^ Weisstein, Eric W. "Kittell Graph". MathWorld.
  2. ^ Kittell, Irving (1935), "A group of operations on a partially colored map" (PDF), Bulletin of the American Mathematical Society, 41 (6): 407–413, doi:10.1090/S0002-9904-1935-06104-X, MR 1563103