{ "id": "math/0603285", "version": "v1", "published": "2006-03-13T09:49:56.000Z", "updated": "2006-03-13T09:49:56.000Z", "title": "Enumeration of 3-letter patterns in compositions", "authors": [ "S. Heubach", "T. Mansour" ], "comment": "20 pages, 1 figure; accepted for the Proceedings of the 2005 Integer Conference", "categories": [ "math.CO" ], "abstract": "Let A be any set of positive integers and n a positive integer. A composition of n with parts in A is an ordered collection of one or more elements in A whose sum is n. We derive generating functions for the number of compositions of n with m parts in A that have r occurrences of 3-letter patterns formed by two (adjacent) instances of levels, rises and drops. We also derive asymptotics for the number of compositions of n that avoid a given pattern. Finally, we obtain the generating function for the number of k-ary words of length m which contain a prescribed number of occurrences of a given pattern as a special case of our results.", "revisions": [ { "version": "v1", "updated": "2006-03-13T09:49:56.000Z" } ], "analyses": { "subjects": [ "05A05", "05A15", "05A16" ], "keywords": [ "composition", "enumeration", "positive integer", "generating function", "special case" ], "tags": [ "conference paper" ], "note": { "typesetting": "TeX", "pages": 20, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2006math......3285H" } } }