Wells graph

The Wells graph is the unique distance-regular graph with intersection array ${\displaystyle \{5,4,1,1;1,1,4,5\}.}$

Its spectrum is ${\displaystyle 5^{1}{\sqrt {5}}^{8}1^{10}(-{\sqrt {5}})^{8}(-3)^{5}}$. Its queue number is 3 and an upper bound on its book thickness is 5.

• A.E. Brouwer's website: The Armanios-Wells graph