{ "id": "0804.3750", "version": "v5", "published": "2008-04-23T15:56:45.000Z", "updated": "2009-02-07T09:43:28.000Z", "title": "Mixed sums of squares and triangular numbers (III)", "authors": [ "Byeong-Kweon Oh", "Zhi-Wei Sun" ], "journal": "J. Number Theory 129(2009), no.4, 964-969", "categories": [ "math.NT", "math.CO" ], "abstract": "In this paper we confirm a conjecture of Sun which states that each positive integer is a sum of a square, an odd square and a triangular number. Given any positive integer m, we show that p=2m+1 is a prime congruent to 3 modulo 4 if and only if T_m=m(m+1)/2 cannot be expressed as a sum of two odd squares and a triangular number, i.e., p^2=x^2+8(y^2+z^2) for no odd integers x,y,z. We also show that a positive integer cannot be written as a sum of an odd square and two triangular numbers if and only if it is of the form 2T_m (m>0) with 2m+1 having no prime divisor congruent to 3 modulo 4.", "revisions": [ { "version": "v5", "updated": "2009-02-07T09:43:28.000Z" } ], "analyses": { "subjects": [ "11E25", "05A05", "11D85", "11P99", "11Y11" ], "keywords": [ "triangular number", "mixed sums", "odd square", "positive integer", "prime divisor congruent" ], "tags": [ "journal article" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2008arXiv0804.3750O" } } }