Abstract:
We consider undirected graphs without loops and multiple edges. Previously, V. P. Burichenko and A. A. Makhnev [Modern Problems in Mathematics: Proc. 42nd All-Russian School–Conference of Young Scientists, Yekaterinburg, Institute of Mathematics and Mechanics, UB RAS, 2011, 181–183] found intersection arrays of distance-regular locally cyclic graphs with the number of vertices at most 1000. It is shown that the automorphism group of a graph with intersection array $\{15,12,1;1,2,15\}$, $\{35,32,1;1,2,35\}$, $\{39,36,1;1,2,39\}$ or $\{42,39,1;1,3,42\}$ (such a graph enters the above-mentioned list) acts intransitively on the set of its vertices.