On the domination number of generalized Petersen graphs

Let G = ( V ( G ) , E ( G ) ) be a graph. A set S ⊆ V ( G ) is a dominating set if every vertex of V ( G ) − S is adjacent to some vertex in S . The domination number γ ( G ) of G is the minimum cardinality of a dominating set of G . In this paper, we study the domination number of generalized Petersen graphs P ( n , 2 ) and prove that γ ( P ( n , 2 ) ) = n − ⌊ n 5 ⌋ − ⌊ n + 2 5 ⌋ .