A Double Binomial Sum: Putnam 35-A4 Revisited

作者:Tuenter Hans J H*
来源:American Mathematical Monthly, 2015, 122(7): 684-689.
DOI:10.4169/amer.math.monthly.122.7.684

摘要

We show that a double binomial sum identity that arises in the context of Hadamard matrices can be reduced to a convolution over a simpler binomial sum that was featured in the 1974 Putnam Mathematical Competition. The proof uses the fact that these binomial sums can be interpreted as moments of a symmetric Bernoulli random walk.

  • 出版日期2015-9

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