This is one of two rank-3 strongly regular graphs with parameters $(256,45,16,6)$, the other graph being the $\mathrm{H}_2(4,2)$ graph.
| Number of vertices: | $256$ |
| Diameter: | $2$ |
| Intersection array: | $\{45,28;1,6\}$ |
| Spectrum: | $45^1 13^{45} (-3)^{210}$ |
| Automorphism group: | $2^8:\mathrm{S}_{10}$ |
| Distance-transitive: | Yes |
| Primitive |