05C69 05C15 2 05C25 1 05C60 1 16D10 1 Helm graph 1 \(\mathcal{D}\)-equivalence class 1 chromatic number 1 clique cover 1 clique number 1 co-intersection graph 1 colour class domination number 1 connected dominating set 1 domination polynomial 1 double fan graph 1 friendship graphs 1 global domination 1 global outer connected domination 1 outer connected domination 1 semi complete graph 1 sun flower graph 1 total dominating set 1 trees 1