{ "id": "1302.5708", "version": "v1", "published": "2013-02-22T21:02:55.000Z", "updated": "2013-02-22T21:02:55.000Z", "title": "An Unexpected Congruence Modulo 5 for 4--Colored Generalized Frobenius Partitions", "authors": [ "James A. Sellers" ], "categories": [ "math.NT" ], "abstract": "In his 1984 AMS Memoir, George Andrews defined the family of $k$--colored generalized Frobenius partition functions. These are denoted by $c\\phi_k(n)$ where $k\\geq 1$ is the number of colors in question. In that Memoir, Andrews proved (among many other things) that, for all $n\\geq 0,$ $c\\phi_2(5n+3) \\equiv 0\\pmod{5}.$ Soon after, many authors proved congruence properties for various $k$--colored generalized Frobenius partition functions, typically with a small number of colors. In 2011, Baruah and Sarmah proved a number of congruence properties for $c\\phi_4$, all with moduli which are powers of 4. In this brief note, we add to the collection of congruences for $c\\phi_4$ by proving this function satisfies an unexpected result modulo 5. The proof is elementary, relying on Baruah and Sarmah's results as well as work of Srinivasa Ramanujan.", "revisions": [ { "version": "v1", "updated": "2013-02-22T21:02:55.000Z" } ], "analyses": { "subjects": [ "05A17", "11P83" ], "keywords": [ "unexpected congruence modulo", "colored generalized frobenius partition functions", "congruence properties", "brief note", "george andrews" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1302.5708S" } } }