A survey on packing colorings
Boštjan Brešar, Jasmina Ferme, Sandi Klavžar, Douglas F. Rall · Discussiones Mathematicae Graph Theory · 2020
If S = (a 1 , a 2 , . . .) is a non-decreasing sequence of positive integers, then an S-packing coloring of a graph G is a partition of V (G) into sets X 1 , X 2 , . . . such that for each pair of distinct vertices in the set X i , the distance between them is larger than a i . If there exists an integer k such that