{ "id": "2407.07366", "version": "v1", "published": "2024-07-10T04:54:43.000Z", "updated": "2024-07-10T04:54:43.000Z", "title": "Counting Permutations in $S_{2n}$ and $S_{2n+1}$", "authors": [ "Yuewen Luo" ], "categories": [ "math.CO" ], "abstract": "Let $\\alpha(n)$ denote the number of perfect square permutations in the symmetric group $S_n$. The conjecture $\\alpha(2n+1) = (2n+1) \\alpha(2n)$, provided by Stanley[4], was proved by Blum[1] using a generating function. This paper presents a combinatorial proof for this conjecture. At the same time, we demonstrate that all permutations with an even number of even cycles in both $S_{2n}$ and $S_{2n+1}$ can be categorized into three distinct types that correspond to each other.", "revisions": [ { "version": "v1", "updated": "2024-07-10T04:54:43.000Z" } ], "analyses": { "keywords": [ "counting permutations", "perfect square permutations", "symmetric group", "conjecture", "combinatorial proof" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }