The Nonexistence of a Distance-Regular Graph with Intersection Array {22,16,5;1,2,20}

Supalak Sumalroj, Chalermpong Worawannotai


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.


Distance-regular graph; Nonexistence; Partial linear space

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