The nonexistence of a distance-regular graph with intersection array {22,16,5;1,2,20}

Abstract

We prove that a distance-regular graph with intersection array {22; 16; 5; 1; 2; 20} does not exist. To prove this, we assume that such a graph exists and derive some combinatorial properties of its local graph. Then we construct a partial linear space from the local graph to display the contradiction.