R(4,7) > 48

The two coloring of the edges of K48 which established the lower bound is available as a 0-1 adjacency matrix in which color 0 is K4-free and color 1 is K7-free.

This was a two step construction. First a circulant graph was found with relatively few bad subgraphs, then via simulated annealing, the bad subgraphs were eliminated.

Geoff Exoo