There exists no distance-regular graph with intersection array {56,36,9;1,3,48}

Abstract

We prove that a distance-regular graph with intersection array {56,36,9;1,3,48} does not exist. This intersection array is from the table of feasible parameters for distance-regular graphs in "Distance-regular graphs"\ by A.E. Brouwer, A.M. Cohen, A. Neumaier.