4-Chromatic Graphs Have At Least 4 Cycles of Length $0\mathrm{mod}3$

Sean Kim, Michael E. Picollelli

A 2018 conjecture of Brewster, McGuinness, Moore, and Noel asserts that for $k\ge 3$, if a graph has chromatic number greater than $k$, then it contains at least as many cycles of…