The Ground Breaking Work of Geoffrey Exoo and Dan Ismailescu: October Issue (2); Vol XXVI

By G. Exoo and D. Ismailescu
By G. Exoo and D. Ismailescu

This is Exoo’s and Ismailescu’s triangle-free, 4 chromatic unit distance graph of order 17 – a World Record.

It comes from the essay “Small Order Triangle-Free 4 Chromatic Unit Distance Graphs” that appear in the October issue (2) of Volume XXVI.