{ "id": "2101.01928", "version": "v1", "published": "2021-01-06T08:53:09.000Z", "updated": "2021-01-06T08:53:09.000Z", "title": "Transformation à la Foata for special kinds of descents and excedances", "authors": [ "Jean-Luc Baril", "Sergey Kirgizov" ], "comment": "12 pages, 2 figures", "categories": [ "math.CO", "cs.DM" ], "abstract": "A pure excedance in a permutation $\\pi=\\pi_1\\pi_2\\ldots \\pi_n$ is a position $i<\\pi_i$, $1\\leq i\\leq n-1$, so that there is no $j