{ "id": "0912.2671", "version": "v4", "published": "2009-12-14T19:26:25.000Z", "updated": "2009-12-20T04:51:41.000Z", "title": "Curious congruences for Fibonacci numbers", "authors": [ "Zhi-Wei Sun" ], "comment": "16 pages. Revise Conj. 4.2", "categories": [ "math.NT", "math.CO" ], "abstract": "In this paper we establish some sophisticated congruences involving central binomial coefficients and Fibonacci numbers. For example, we show that if $p\\not=2,5$ is a prime then $$\\sum_{k=0}^{p-1}F_{2k}\\binom{2k}{k}=(-1)^{[p/5]}(1-(p/5)) (mod p^2)$$ and $$\\sum_{k=0}^{p-1}F_{2k+1}\\binom{2k}k=(-1)^{[p/5]}(p/5) (mod p^2).$$ We also obtain similar results for some other second-order recurrences and raise several conjectures.", "revisions": [ { "version": "v4", "updated": "2009-12-20T04:51:41.000Z" } ], "analyses": { "subjects": [ "11B39", "11B65", "05A10", "11A07" ], "keywords": [ "fibonacci numbers", "curious congruences", "central binomial coefficients", "similar results", "second-order recurrences" ], "note": { "typesetting": "TeX", "pages": 16, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0912.2671S" } } }