In the mathematical field of graph theory, the Robertson–Wegner graph is a 5-regular undirected graph with 30 vertices and 75 edges named after Neil Robertson and Gerd Wegner.
[2][3][4] It is one of the four (5,5)-cage graphs, the others being the Foster cage, the Meringer graph, and the Wong graph.
It has chromatic number 4, diameter 3, and is 5-vertex-connected.
The characteristic polynomial of the Robertson–Wegner graph is