Integral sum graphs G_n and G_-r,n are perfect graphs

Figures & data

Fig. 1 $G_{13}:$ vertex coloring and clique.

Fig. 2 $G_{13}:$ edge coloring.

Fig. 3 $G_{0,12}:$ vertex coloring and clique.

Fig. 4 $G_{0,12}:$ edge coloring.

Fig. 5 $G_{-5,7}:$ vertex coloring.

Fig. 6 $G_{-5,7}$ with edge coloring.

Fig. 7 $G_{-8,3}$ with edge coloring.