• The coordination sequence up to distance 10. A vertex v is at distance k of u is there is a chain of k + 1 vertices u = u 0 , u 1 , . . . , u k = v such that for all i in ⟦1, k⟧ (where ⟦a, b⟧ designates the set of integers between a and b), u i-1 and u i are neighbours, and there is no smaller such chain. The k-th term of the coordination sequence of u is then defined as the number of vertices at distance k of u. • The point symbol.