{ "id": "0909.2598", "version": "v1", "published": "2009-09-14T17:06:16.000Z", "updated": "2009-09-14T17:06:16.000Z", "title": "The divisibility of a^n-b^n by powers of n", "authors": [ "Chris Smyth" ], "categories": [ "math.NT" ], "abstract": "For given integers a,b, and j at least 1 we determine the set of integers n for which a^n-b^n is divisible by n^j. For j=1,2, this set is usually infinite; we find explicitly the exceptional cases for which a,b the set is finite. For j=2, we use Zsigmondy's Theorem for this. For j at least 3 and gcd(a,b)=1, the set is probably always finite; this seems difficult to prove, however. We also show that determination of the set of integers n for which a^n+b^n is divisible by n^j can be reduced to that of the above set.", "revisions": [ { "version": "v1", "updated": "2009-09-14T17:06:16.000Z" } ], "analyses": { "subjects": [ "11B37", "11D61" ], "keywords": [ "divisibility", "exceptional cases", "zsigmondys theorem" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0909.2598S" } } }