In 1934, Franklin published a counterexample to the Heawood conjecture, this 12-vertex cubic graph is now known as the Franklin graph.
Goldbach's conjecture | ''n''! conjecture | n! conjecture | Kato's conjecture | Calabi conjecture | Weil conjecture | ''Uncle Petros and Goldbach's Conjecture'' by Apostolos Doxiadis | Uncle Petros and Goldbach's Conjecture | Schanuel's conjecture | Pollock's conjecture | Mumford conjecture | Kepler conjecture | Heawood conjecture | Chang's conjecture | Catalan's conjecture | Blattner's conjecture | Beal's conjecture |