{ "id": "2506.14312", "version": "v2", "published": "2025-06-17T08:42:49.000Z", "updated": "2025-06-20T08:51:09.000Z", "title": "Schreier Sets of Multiples of an Integer, Linear Recurrence, and Pascal Triangle", "authors": [ "Hung Viet Chu", "Zachary Louis Vasseur" ], "comment": "14 pages, 4 tables", "categories": [ "math.CO", "math.NT" ], "abstract": "A finite nonempty set $F$ is said to be Schreier (maximal Schreier, respectively) if $\\min F\\ge |F|$ ($\\min F = |F|$, respectively). For $k,n\\in\\mathbb{N}$, let $$s_{k,n}\\ :=\\ |\\{F\\subset\\{k, 2k,\\ldots, nk\\}\\,:\\, F\\mbox{ is Schreier and }nk\\in F\\}|.$$ We show that $(s_{k,n})_{n=1}^\\infty$ is a subsequence with terms taken periodically from the Padovan-like sequence $(a_{k,n})_{n=0}^\\infty$ defined as: $a_{k,0} = a_{k,1} = 1, a_{k, 2} = \\cdots = a_{k, k} = 2$, and $$a_{k, n}\\ =\\ a_{k,n-k} + a_{k,n-k-1},\\mbox{ for } n\\ge k+1.$$ As an application, we obtain an alternative proof of the linear recurrence of $(s_{k,n})_{n=1}^\\infty$ discovered by Beanland et al. Furthermore, a similar result holds for the sequence $(s^{(m)}_{k,n})_{n=1}^\\infty$ that counts maximal Schreier sets. Finally, we prove that $$s^{(m)}_{k,n}\\ =\\ 2s_{k,n}-s_{k,n+1}, \\mbox{ for all }n\\ge 1.$$", "revisions": [ { "version": "v2", "updated": "2025-06-20T08:51:09.000Z" } ], "analyses": { "subjects": [ "05A19", "11B37", "11Y55", "05A15" ], "keywords": [ "linear recurrence", "pascal triangle", "counts maximal schreier sets", "similar result holds", "finite nonempty set" ], "note": { "typesetting": "TeX", "pages": 14, "language": "en", "license": "arXiv", "status": "editable" } } }