{ "id": "0907.3412", "version": "v2", "published": "2009-07-20T14:51:34.000Z", "updated": "2011-12-27T15:52:24.000Z", "title": "The 2-adic valuations of Stirling numbers of the second kind", "authors": [ "Shaofang Hong", "Jianrong Zhao", "Wei Zhao" ], "comment": "9 pages. To appear in International Journal of Number Theory", "journal": "International J. Number Theory 8 (2012), 1057--1066", "categories": [ "math.NT" ], "abstract": "In this paper, we investigate the 2-adic valuations of the Stirling numbers $S(n, k)$ of the second kind. We show that $v_2(S(4i, 5))=v_2(S(4i+3, 5))$ if and only if $i\\not\\equiv 7\\pmod {32}$. This confirms a conjecture of Amdeberhan, Manna and Moll raised in 2008. We show also that $v_2(S(2^n+1, k+1))= s_2(n)-1$ for any positive integer $n$, where $s_2(n)$ is the sum of binary digits of $n$. It proves another conjecture of Amdeberhan, Manna and Moll.", "revisions": [ { "version": "v2", "updated": "2011-12-27T15:52:24.000Z" } ], "analyses": { "subjects": [ "11B73", "11A07" ], "keywords": [ "second kind", "stirling numbers", "valuations", "binary digits" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 9, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0907.3412H" } } }