Conjecture on the maximum 7- and 8-distance sets in triangular lattices

From papers

Let a triangular lattice be the set of points with coordinates a(1,0)+b(12,32)a(1,0)+b(\frac12,\frac{\sqrt3}{2}), where a,bZa,b\in\mathbb Z. An mm-distance set is a set of lattice points whose pairwise distances take at most mm values, and a maximum mm-distance set has largest possible size. A regular hexagon with side length 22 is understood as the corresponding hexagonal region of the triangular lattice. Maximum 7- and 8-distance conjecture. The maximum 77-distance and 88-distance sets have 1616 and 1919 points, respectively. The 77-distance set can only be realized by taking all triangular-lattice points in a regular hexagon with side length 22 and removing three mutually adjacent or three mutually non-adjacent corners. The 88-distance set can only be realized by taking all points in that regular hexagon. These are presented as conjectures based on the authors' constructions; no proof or resolution is supplied.

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Primary source

Li-Ren Bao and Wei-Hsuan Yu, “Constructions of Large m-Distance Sets on Triangular Lattice”, arXiv:2509.00880 (2025).

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