{ "id": "0801.1097", "version": "v2", "published": "2008-01-07T19:49:15.000Z", "updated": "2008-05-29T10:17:04.000Z", "title": "A Combinatorial Interpretation for Certain Relatives of the Conolly Sequence", "authors": [ "B. Balamohan", "Zhiqiang Li", "Stephen Tanny" ], "comment": "13 pages, 6 figures, 1 table", "journal": "Journal of Integer Sequences, Vol. 11 (2008), Article 08.2.1", "categories": [ "math.CO" ], "abstract": "For any integer s >= 0, we derive a combinatorial interpretation for the family of sequences generated by the recursion (parameterized by s) h_s(n) = h_s(n - s - h_s(n - 1)) + h_s(n - 2 - s - h_s(n - 3)), n > s + 3, with the initial conditions h_s(1) = h_s(2) = ... = h_s(s+2) = 1 and h_s(s+3) = 2. We show how these sequences count the number of leaves of a certain infinite tree structure. Using this interpretation we prove that h_s sequences are \"slowly growing\", that is, h_s sequences are monotone nondecreasing, with successive terms increasing by 0 or 1, so each sequence hits every positive integer. Further, for fixed s the sequence h_s(n) hits every positive integer twice except for powers of 2, all of which are hit s+2 times. Our combinatorial interpretation provides a simple approach for deriving the ordinary generating functions for these sequences.", "revisions": [ { "version": "v2", "updated": "2008-05-29T10:17:04.000Z" } ], "analyses": { "subjects": [ "05A15", "11B37", "11B39" ], "keywords": [ "combinatorial interpretation", "conolly sequence", "infinite tree structure", "initial conditions", "sequences count" ], "tags": [ "journal article" ], "publication": { "journal": "Journal of Integer Sequences", "year": 2008, "month": "May", "volume": 11, "number": 2, "pages": 21 }, "note": { "typesetting": "TeX", "pages": 13, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2008JIntS..11...21B" } } }