New Types Of Integral Sum Graphs

Harary (Discrete Math, 124(1-3) (1994) 99) introduced the intergral sum graphs, and proved that the path P-m and matching mK(2) are integer sum graphs, and offered some conjectures, In this paper we enlarge the types of integral sum graphs. We prove that some caterpillars and mP(n) are integral sum graphs and some conjectures of Harary are wrong. (C) 2002 Elsevier Science B.V. All rights reserved.