The Strongly Regular $(45,12,3,3)$ Graphs

Abstract

Using two backtrack algorithms based on different techniques, designed and implemented independently, we were able to determine up to isomorphism all strongly regular graphs with parameters $v=45$, $k=12$, $\lambda=\mu=3$. It turns out that there are $78$ such graphs, having automorphism groups with sizes ranging from $1$ to $51840$.