"Order" is the number of vertices. Terms are listed from smallest to largest, with duplications when there exist multiple graphs with the same order.
Table of n, a(n) for n=1..13.
Wikipedia, Cubic distance-regular graphs
4 is a term because the tetrahedron graph is cubic and distance-regular and has order 4.
20 is a term because the dodecahedron graph is cubic and distance-regular and has order 20.
Cf. A328144 (cubic distance-transitive graphs), A075124 (cubic symmetric graphs).
Sequence in context: A067315 A069148 A328144 * A103800 A022449 A088686
Adjacent sequences: A327885 A327886 A327887 * A327889 A327890 A327891
Harry Richman, Sep 29 2019