A note on 2-odd labeling of graphs

A graph G=(V(G), E(G)) is a 2−odd graph if there exists an injective function f: V(G)→Z (the set of all integers) such that for any two adjacent vertices x and y, the integer | f(x) – f(y) | is either odd or exactly 2. So G is a 2−odd graph if and only if there exists 2−odd labeling of G. In this paper, we derive 2−odd labeling of some special graphs such as triangular snake graph Tn, double triangular snake graph DTn, triple triangular snake graph TTn, and alternate triangular snake graph ATn.