We say (n, e) (m, f), an (m, f) subgraph is forced, if every n-vertex graph of size e has an m-vertex spanned subgraph with f edges. For example, as Tur
For an arbitrary subset P of the reals, we define a function f: V P to be a Pdominating function of graph G = (V, E) if the sum of the function values over any
A defining set (of vertex coloring) of a graph G is a set of vertices S with an assignment of colors to its elements which has a unique completion to a proper coloring of G. We de...
Hossein Hajiabolhassan, Mojtaba L. Mehrabadi, Ruzb...
Mosaics are orbits of partitions arising from music theoretical investigations. Various theorems from the field of "enumeration under finite group actions" are applied f...
Let Fk(x) = n=0 Fk n xn . Using the interpretation of Fibonacci numbers in the terms of Morse codes, we give a bijective proof of Riordan's formula (1 - Lkx + (-1)k x2 )Fk(x...
We characterize bipartite Steinhaus graphs in three ways by partitioning them into four classes and we describe the color sets for each of these classes. An interesting recursion ...
Gerard J. Chang, Bhaskar DasGupta, Wayne M. Dym&ag...
Let G be a simple graph with n( 2) vertices, and i(G) be the ith largest eigenvalue of G. In this paper we obtain the following: If 3(G) < 0, and there exists some index k, 2 ...
We construct a bijection between labeled trees and allowable pairs of permutations sorted by a priority queue. These are also the pairs of permutations that avoid the pattern pairs...