Problem 59841. Count the ways to write 1/n as the sum of two unit fractions

ChrisR

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The number 1/2 can be written as 1/3+1/6 and 1/4+1/4, and the number 1/9 can be written as 1/18+1/18, 1/12+1/36, and 1/10+1/90. That is, 1/2 can be written as the sum of two unit fractions (those with a numerator of 1) in two ways, and 1/9 can be written as the sum of two unit fractions in three ways. 
Write a function to count the ways  can be written as the sum of two unit fractions.

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Last Solution submitted on Jul 20, 2026

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