On Mod(2)-Edge-Magic Graphs

Dharam Chopra1, Rose Dios2, Sin-Min Lee3
1Department of Mathematics and Statistics Wichita State University Wichita, KS 67260, USA
2Department of Mathematical Sciences New Jersey Institute of Technology Newark, NJ 07102 USA
3Department of Computer Science San Jose State University San Jose, California 95192 U.S.A.

Abstract

Let \( G \) be a \((p,q)\)-graph where each edge of \( G \) is labeled by a number \( 1, 2, \ldots, q \) without repetition. The vertex sum for a vertex \( v \) is the sum of the labels of edges that are incident to \( v \). If the vertex sums are equal to a constant (mod \( k \)) where \( k \geq 2 \), then \( G \) is said to be Mod(\( k \))-edge-magic. In this paper, we investigate graphs which are Mod(\( k \))-edge-magic. When \( k = p \), the corresponding Mod(\( p \))-edge-magic graph is the edge-magic graph introduced by Lee (third author), Seah, and Tan in \([10]\). In this work, we investigate trees, unicyclic graphs, and \((p, p+1)\)-graphs which are Mod(2)-edge-magic.

Keywords: Mod(k)-edge-magic, unicyclic, (p,p+1)-graph.