A graph Γ is G-symmetric if Γ adimits G as a group of automorphisms acting transitively on the set of vertices and the set of arcs of Γ, where an arc is an ordered pair of adjacent vertices.In the cas
We give a criterion for the log-convexity (resp.the strong q-log-convexity) in terms of certain infinite triangular array of nonnegative numbers (resp.of polynomials in q with nonnegative coefficients
A fullerene graph is a cubic 3-connected plane graph with exact 12 pentagons and other hexagons.In the present work, by Rayleighs short-cut method and Fosters formulas, we show that in a fullerene gra
For a square primitive nonpowerful sign pattern A, the base of A, denoted byl(A), is the least positive integer l such that every entry of Al is #.The base of a sign pattern is closely related to many