On 2-Rainbow Domination Number Of Generalized Petersen Graphs P(5k,K)

We obtain new results on 2-rainbow domination number of generalized Petersen graphs P(5k,k). In some cases (for some infinite families), exact values are established, and in all other cases lower and upper bounds are given. In particular, it is shown that, for k > 3, gamma(r2)(P(5k,k)) = 4k for k 2,8 mod 10, gamma(r2)(P(5k,k)) = 4k + 1 for k 5,9 mod 10, 4k + 1 <= gamma(r2)(P(5k,k)) <= 4k + 2 for k 1,6,7 mod 10, and 4k + 1 <= gamma(r2)(P(5k,k)) <= 4k + 3 for k 0,3,4 mod 10.