{ "id": "1511.06221", "version": "v1", "published": "2015-11-17T01:36:25.000Z", "updated": "2015-11-17T01:36:25.000Z", "title": "Proof of some congruences conjectured by Guo and Liu", "authors": [ "Guo-Shuai Mao" ], "comment": "14 pages, 0 figures", "categories": [ "math.NT", "math.CO" ], "abstract": "Let $n$ and $r$ be positive integers and $p$ a prime. Define the numbers $S_n^{(r)}$ and $T_n^{(r)}$ by $$S_n^{(r)}=\\sum_{k=0}^n\\binom{n}{k}^2\\binom{2k}{k}(2k+1)^r\\ \\mbox{,}\\ T_n^{(r)}=\\sum_{k=0}^n\\binom{n}{k}^2\\binom{2k}{k}(2k+1)^r(-1)^k.$$ In this paper we first prove the following congruences: $$\\sum_{k=0}^{n-1}S_k^{(2r)}\\equiv0\\pmod{n^2},$$ $$\\sum_{k=0}^{n-1}T_k^{(2r)}\\equiv0\\pmod{n^2}$$ and $$\\sum_{k=0}^{p-1}T_k^{(2)}\\equiv\\frac{p^2}{2}\\left(5-3\\big(\\frac{p}{5}\\big)\\right)\\pmod{p^3}.$$ We also show that there exist integers $a_{2r-1}$ and $b_r$, independent of n, such that $$a_{2r-1}\\sum_{k=0}^{n-1}S_k^{(2r-1)}\\equiv0\\pmod{n^2},$$ $$b_r\\sum_{k=0}^{n-1}kS_k^{(r)}\\equiv0\\pmod{n^2}.$$ This confirms several recent conjectures of Guo and Liu.", "revisions": [ { "version": "v1", "updated": "2015-11-17T01:36:25.000Z" } ], "analyses": { "keywords": [ "congruences", "conjectures", "positive integers" ], "note": { "typesetting": "TeX", "pages": 14, "language": "en", "license": "arXiv", "status": "editable" } } }