#The collapsed adjacency matrices were computed by C. E. Praeger and L. H. Soicher. mats:=[ [ [ 1, 0, 0, 0 ], [ 0, 1, 0, 0 ], [ 0, 0, 1, 0 ], [ 0, 0, 0, 1 ] ], [ [ 0, 1, 0, 0 ], [ 1, 0, 0, 0 ], [ 0, 0, 0, 1 ], [ 0, 0, 1, 0 ] ], [ [ 0, 0, 21, 0 ], [ 0, 0, 0, 21 ], [ 1, 0, 20, 0 ], [ 0, 1, 0, 20 ] ], [ [ 0, 0, 0, 21 ], [ 0, 0, 21, 0 ], [ 0, 1, 0, 20 ], [ 1, 0, 20, 0 ] ] ];