The Rijeka graph is the first-known example of a strongly regular graph with parameters . It arises from an imprimitive
action of the group
and was discovered by Crnković et al. (2018).
It is distance-regular (but not distance-transitive)
and has intersection array
and graph spectrum
.
The name "Rijeka graph" was introduced on DistanceRegular.org in honor of the city of Rijeka, Croatia in which the university of the discoverers is located.