On 3‐colorings of bipartite p‐threshold graphs
Ioan Tomescu · Journal of Graph Theory · 1987
Abstract In this paper some extremal properties of 3‐colorings of bipartite complete graphs in the class of all bipartite p‐threshold graphs that are uniquely 2‐colorable are proved. As a consequence it is shown that the complete bipartite graphs Kp, p + r where p ⩾ 2 and 0 ⩽ r < magnified image are chromatically unique. A useful result concerning the maximization of a sum of powers of two under certain restrictions, which has an arithmetical interest, is also presented.