{ "id": "math/0411557", "version": "v2", "published": "2004-11-24T17:25:12.000Z", "updated": "2004-12-13T13:37:00.000Z", "title": "The number of matroids on a finite set", "authors": [ "W. M. B. Dukes" ], "comment": "10 pages; revised proofs and corrected typos", "categories": [ "math.CO" ], "abstract": "In this paper we highlight some enumerative results concerning matroids of low rank and prove the tail-ends of various sequences involving the number of matroids on a finite set to be log-convex. We give a recursion for a new, slightly improved, lower bound on the number of rank-$r$ matroids on $n$ elements when $n=2^m-1$. We also prove an adjacent result showing the point-lines-planes conjecture to be true if and only if it is true for a special subcollection of matroids. Two new tables are also presented, giving the number of paving matroids on at most eight elements.", "revisions": [ { "version": "v2", "updated": "2004-12-13T13:37:00.000Z" } ], "analyses": { "subjects": [ "05B35" ], "keywords": [ "finite set", "low rank", "enumerative results concerning matroids", "lower bound", "point-lines-planes conjecture" ], "note": { "typesetting": "TeX", "pages": 10, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2004math.....11557D" } } }