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arXiv math/0510079math.CO
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对Shalosh B. Ekhad的10^n格路定理

A human proof for a generalization of Shalosh B. Ekhad's 10^n Lattice Paths Theorem

Nicholas A. Loehr, Bruce E. Sagan, Gregory S. Warrington

摘要:

考虑Z^2中的格点路径,向北(N)和向东(E)各取一个单位步长。固定正整数r,s,并在Z ^2上的点上建立一个等价关系,设v,w是等价的,如果v - w = m(r,s),其中m在Z中。称一条格路有效,如果每当它以E步进入一个点v时,那么v类中的任何其他点也以E步进入。Loehr和Warrington证明了从(0,0)到(nr,ns)的有效路径数是(r+s choose r)^n。当s = 2时,我们证明了这个猜想。

英文摘要:

Consider lattice paths in Z^2 taking unit steps north (N) and east (E). Fix positive integers r,s and put an equivalence relation on points of Z^2 by letting v,w be equivalent if v - w = m (r,s) for some m in Z. Call a lattice path valid if whenever it enters a point v with an E-step, then any further points of the path in the class of v are also entered with an E-step. Loehr and Warrington conjectured that the number of valid paths from (0,0) to (nr,ns) is (r+s choose r)^n. We prove this conjecture when s = 2.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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