{ "id": "1208.5993", "version": "v3", "published": "2012-08-29T19:08:36.000Z", "updated": "2012-12-12T21:36:42.000Z", "title": "Γ-species and the enumeration of k-trees", "authors": [ "Andrew Gainer-Dewar" ], "comment": "26 pages; includes Python code", "journal": "Electronic Journal of Combinatorics, 19(4) (2012), #P45", "categories": [ "math.CO" ], "abstract": "We study the class of graphs known as k-trees through the lens of Joyal's theory of combinatorial species (and an equivariant extension known as '$\\Gamma$-species' which incorporates data about 'structural' group actions). This culminates in a system of recursive functional equations giving the generating function for unlabeled k-trees which allows for fast, efficient computation of their numbers. Enumerations up to k = 10 and n = 30 (for a k-tree with (n+k-1) vertices) are included in tables, and Sage code for the general computation is included in an appendix.", "revisions": [ { "version": "v3", "updated": "2012-12-12T21:36:42.000Z" } ], "analyses": { "subjects": [ "05C30", "05E18" ], "keywords": [ "enumeration", "combinatorial species", "equivariant extension", "incorporates data", "group actions" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 26, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1208.5993G" } } }