Generalization and Probabilistic Proof of a Combinatorial Identity

作者:Chang Guisong*; Xu Chen
来源:American Mathematical Monthly, 2011, 118(2): 175-177.
DOI:10.4169/amer.math.monthly.118.02.175

摘要

In this note, we give a probabilistic proof of a combinatorial identity which involves binomial coefficients. Our results consist of showing that the identity essentially computes the moment of order a of the chi-square random variable with m degrees of freedom.

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