{ "id": "1109.2340", "version": "v3", "published": "2011-09-11T19:10:10.000Z", "updated": "2011-10-19T17:56:41.000Z", "title": "An Extension of a Congruence by Kohnen", "authors": [ "Romeo Mestrovic" ], "comment": "13 pages; This is the same as version 2 with extended Remarks on page 3 concerning a search of Euler numbers arising supercongruences and a new conjecture on page 4", "categories": [ "math.NT" ], "abstract": "Let $p>3$ be a prime, and let $q_p(2)=(2^{p-1}-1)/p$ be the Fermat quotient of $p$ to base 2. Recently, Z. H. Sun proved that \\sum_{k=1}^{p-1}\\frac{1}{k\\cdot 2^k}\\equiv q_p(2)-\\frac{p}{2}q_p(2)^2 \\pmod{p^2} which is a generalization of a congruence due to W. Kohnen. In this note we give an elementary proof of the above congruence which is based on several combinatorial identities and congruences involving the Fermat quotient $q_p(2)$, harmonic or alternating harmonic sums.", "revisions": [ { "version": "v3", "updated": "2011-10-19T17:56:41.000Z" } ], "analyses": { "subjects": [ "11B75", "11A07", "11B65", "05A10" ], "keywords": [ "congruence", "fermat quotient", "elementary proof", "combinatorial identities", "alternating harmonic sums" ], "note": { "typesetting": "TeX", "pages": 13, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2011arXiv1109.2340M" } } }