{ "id": "1511.00478", "version": "v1", "published": "2015-11-02T12:51:36.000Z", "updated": "2015-11-02T12:51:36.000Z", "title": "On the number of representations of n as a linear combination of four triangular numbers II", "authors": [ "Min Wang", "Zhi-Hong Sun" ], "comment": "16 pages", "categories": [ "math.NT" ], "abstract": "Let $\\Bbb Z$ and $\\Bbb N$ be the set of integers and the set of positive integers, respectively. For $a,b,c,d,n\\in\\Bbb N$ let $t(a,b,c,d;n)$ be the number of representations of $n$ by $ax(x-1)/2+by(y-1)/2+cz(z-1)/2 +dw(w-1)/2$ $(x,y,z,w\\in\\Bbb Z$). In this paper we obtain explicit formulas for $t(a,b,c,d;n)$ in the cases $(a,b,c,d)=(1,1,2,8),\\ (1,1,2,16),\\ (1,2,3,6),\\ (1,3,4,$ $12),\\ (1,1,3,4),\\ (1,1,5,5)\\ ,(1,5,5,5),\\ (1,3,3,12),\\ (1,1,1,12),\\ (1,1,3,12)$ and $(1,3,3,4)$.", "revisions": [ { "version": "v1", "updated": "2015-11-02T12:51:36.000Z" } ], "analyses": { "subjects": [ "11D85", "11E25" ], "keywords": [ "linear combination", "triangular numbers", "representations" ], "note": { "typesetting": "TeX", "pages": 16, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015arXiv151100478W" } } }