Harmonious labelings of windmill graphs and related graphs
D. Frank Hsu · Journal of Graph Theory · 1982
Abstract A strongly harmonious labeling is the nonmodular version of a harmonious labeling. The windmill graph K(t)n is the graph consisting of t copies of the complete graph Kn with a vertex in common. It is shown that, for t ≥ 1, K(t)n is strongly harmonious and so harmonious by drawing on partitions already available from the construction of cyclic neofields. Other irregular windmill graphs can be shown to be strongly harmonious in a similar way.