{ "id": "1806.03774", "version": "v1", "published": "2018-06-11T02:25:47.000Z", "updated": "2018-06-11T02:25:47.000Z", "title": "Counting subgroups of fixed order in finite abelian groups", "authors": [ "Fikreab Admasu", "Amit Sehgal" ], "comment": "18 pages. Comments welcome!", "categories": [ "math.GR", "math.CO" ], "abstract": "We use recurrence relations to derive explicit formulas for counting the number of subgroups of given order (or index) in rank 3 finite abelian p-groups and use these to derive similar formulas in few cases for rank 4. As a consequence, we answer some questions by M. T$\\ddot{a}$rn$\\ddot{a}$uceanu in \\cite{MT} and L. T$\\dot{\\acute{o}}$th in \\cite{LT}. We also use other methods such as the method of fundamental group lattices introduced in \\cite{MT} to derive a similar counting function in a special case of arbitrary rank finite abelian p-groups.", "revisions": [ { "version": "v1", "updated": "2018-06-11T02:25:47.000Z" } ], "analyses": { "keywords": [ "finite abelian groups", "fixed order", "counting subgroups", "arbitrary rank finite abelian p-groups", "fundamental group lattices" ], "note": { "typesetting": "TeX", "pages": 18, "language": "en", "license": "arXiv", "status": "editable" } } }