An optimal locating-dominating set in the infinite triangular grid Original Research Article

Assume that image is an undirected graph, and image. For every image, we denote by image the set of all elements of C that are within distance one from image. If all the sets image for image are non-empty, and pairwise different, then C is called a locating-dominating set. The smallest possible density of a locating-dominating set in the infinite triangular grid is shown to be image.