Generalized de Bruijn digraphs

We show that the digraphs proposed independently by Imase and Itoh, and Reddy, Pradhan and Kuhl to minimize diameters essentially retain all the nice properties of de Bruijn digraphs and yet are applicable to any number of nodes. In particular we give results on the number of loops, the link connectivities and connectivities, the embedding properties and the self-routing properties for these digraphs.