A strongly regular graph $G$ is a regular graph with the following additional property: there exist two integers $\lambda$ and $\mu$ such that every two adjacent vertices have $\lambda$ common neighbors and every two non-adjacent vertices have $\mu$ common neighbors.
In their book "Algebraic Graph Theory" Godsil and Royle mention the connection of strongly regular graphs with latin squares and thus Orthogonal Arrays (Chapter 10.4). There seems not to be much ...
From what I've read I've gathered the following facts: There are seven known such graphs. Certain parameter sets are ruled out by the Krein conditions and the absolute bound. Beyond that, little or ...