Proper Distance in Edge-Colored Hypercubes

An edge-colored path is called properly colored if no two consecutive edges have the same color. An edge-colored graph is called properly connected if, between every pair of vertices, there is a properly colored path. Moreover, the proper distance between vertices u and v is the length of the shortest properly colored path from u to v. Given a particular class of properly connected colorings of the hypercube, we consider the proper distance between pairs of vertices in the hypercube