Let denote a distance-regular graph with classical parameters (D, b, , ) and D 3. Assume the intersection numbers a1 = 0 and a2 = 0. We show is 3-bounded in the sense of the ar...
Graph searching encompasses a wide variety of combinatorial problems related to the problem of capturing a fugitive residing in a graph using the minimum number of searchers. In t...
We prove that there is no cubic graph with diameter 4 on 40 vertices. This implies that the maximal number of vertices of a (3,4)-graph is 38. ? 2000 Elsevier Science B.V. All rig...
The probability distribution on a set S = { 1, 2, . . . , n } defined by Pr(k) = 1/(Hnk), where Hn in the nth harmonic number, is commonly called a Zipfian distribution. In this no...
An upper bound for the domination number of the direct product of graphs is proved. It in particular implies that for any graphs G and H, γ(G × H) ≤ 3γ(G)γ(H). Graphs with a...