{ "id": "math/0608328", "version": "v1", "published": "2006-08-14T04:07:22.000Z", "updated": "2006-08-14T04:07:22.000Z", "title": "Fleck quotients and Bernoulli numbers", "authors": [ "Zhi-Wei Sun" ], "comment": "38 pages", "categories": [ "math.NT", "math.CO" ], "abstract": "Let p be a prime, and let n>0 and r be integers. In 1913 Fleck showed that $$F_p(n,r)=(-p)^{-[(n-1)/(p-1)]}\\sum_{k=r(mod p)}\\binom{n}{k}(-1)^k\\in\\Z.$$ Nowadays this result plays important roles in many aspects. Recently Sun and Wan investigated $F_p(n,r)$ mod p in [SW2]. In this paper, using p-adic methods we determine $(F_p(m,r)-F_p(n,r))/(m-n)$ modulo p in terms of Bernoulli numbers, where m>0 is an integer with $m\\not=n$ and $m=n (mod p(p-1))$. Consequently, $F_p(n,r)$ mod $p^{ord_p(n)+1}$ is determined; for example, if $n=n_*(mod p-1)$ with $00$ and $l\\ge 0$ are integers with $2\\le n-l\\le p$ then $$\\frac{1}{p^{n-l}}\\sum_{l