MathDB
2017 PUMaC Team 12

Source:

September 20, 2019
number theory

Problem Statement

Call a positive integer nn tubular if for any two distinct primes pp and qq dividing n,(p+q)∣nn, (p + q) | n. Find the number of tubular numbers less than 100,000100,000. (Integer powers of primes, including 1,31, 3, and 1616, are not considered tubular.)
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