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Number of 5-tuples.

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May 25, 2011
number theory unsolvednumber theory

Problem Statement

Let NN be the number of ordered 5-tuples (a1,a2,a3,a4,a5)(a_{1}, a_{2}, a_{3}, a_{4}, a_{5}) of positive integers satisfying
1a1+1a2+1a3+1a4+1a5=1\frac{1}{a_{1}}+\frac{1}{a_{2}}+\frac{1}{a_{3}}+\frac{1}{a_{4}}+\frac{1}{a_{5}}=1
Is NN even or odd?
Oh and HINTS ONLY, please do not give full solutions. Thanks.
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