The mod sum number of the ladder
Hui Yong Yu · Journal of Jilin Institute of Chemical Technology · 2006
The notion of sum graph was introduced by F. Harary in 1990, Mod sum graph and mod sum number were introduced by Boland Sutton etc. A mod sum graph is a sum graph with SZm\{0} and all arithmetic performed modulo where m(≥|S|-1) . The mod sum numberρ(G) of G is the least number p of isolated verticesρK1 such that G∪ρK1 is a mod sum graph. This paper proves that kL3(k≥2) is the mod sum graph, and also is the mod integral sum graph.