Star coloring outerplanar bipartite graphs
Radhika Ramamurthi, Gina Sanders · Discussiones Mathematicae Graph Theory · 2018
A proper coloring of the vertices of a graph is called a star coloring if at least three colors are used on every 4-vertex path. We show that all outerplanar bipartite graphs can be star colored using only five colors and construct the smallest known example that requires five colors.