{ "id": "1702.01249", "version": "v1", "published": "2017-02-04T07:22:45.000Z", "updated": "2017-02-04T07:22:45.000Z", "title": "On the number of representations of certain quadratic forms and a formula for the Ramanujan Tau function", "authors": [ "B. Ramakrishnan", "Brundaban Sahu", "Anup Kumar Singh" ], "comment": "11 pages", "categories": [ "math.NT" ], "abstract": "In this paper, we find the number of representations of the quadratic form $x_1^2+ x_1x_2 + x_2^2 + \\ldots + x_{2k-1}^2 + x_{2k-1}x_{2k} + x_{2k}^2,$ for $k=7,9,11,12,14$ using the theory of modular forms. By comparing our formulas with the formulas obtained by G. A. Lomadze, we obtain the Fourier coefficients of certain newforms of level $3$ and weights $7,9,11$ in terms of certain finite sums involving the solutions of similar quadratic forms of lower variables. In the case of $24$ variables, comparison of these formulas gives rise to a new formula for the Ramanujan Tau function.", "revisions": [ { "version": "v1", "updated": "2017-02-04T07:22:45.000Z" } ], "analyses": { "subjects": [ "11E25", "11F11", "11E20" ], "keywords": [ "ramanujan tau function", "representations", "similar quadratic forms", "lower variables", "fourier coefficients" ], "note": { "typesetting": "TeX", "pages": 11, "language": "en", "license": "arXiv", "status": "editable" } } }