{ "id": "1208.1915", "version": "v2", "published": "2012-08-09T14:03:10.000Z", "updated": "2012-08-21T05:57:41.000Z", "title": "Ascent sequences and 3-nonnesting set partitions", "authors": [ "Sherry H. F. Yan" ], "comment": "arXiv admin note: text overlap with arXiv:math/0510676 by other authors", "categories": [ "math.CO" ], "abstract": "A sequence x=x_1 x_2...x_n $ is said to be an ascent sequence of length $n$ if it satisfies x_1=0 and $0\\leq x_i\\leq asc(x_1x_2...x_{i-1})+1$ for all $2\\leq i\\leq n$, where $asc(x_1x_2... x_{i-1})$ is the number of ascents in the sequence $x_1x_2... x_{i-1}$. Recently, Duncan and Steingr\\'{\\i}msson proposed the conjecture that 210-avoiding ascent sequences of length $n$ are equinumerous with 3-nonnesting set partitions of $\\{1,2,..., n\\}$. In this paper, we confirm this conjecture by showing that 210-avoiding ascent sequences of length $n$ are in bijection with 3-nonnesting set partitions of $\\{1,2,..., n\\}$ via an intermediate structure of growth diagrams for 01-fillings of Ferrers shapes.", "revisions": [ { "version": "v2", "updated": "2012-08-21T05:57:41.000Z" } ], "analyses": { "keywords": [ "set partitions", "ascent sequences", "ferrers shapes" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1208.1915Y" } } }