Prove that for every positive integer , one can find three pairwise coprime positive integers such that the set of prime divisors of and are the same.
Solution
We seek for large enough positive integers such that for some positive integer . Indeed, one can write . Now, choose such that that is, then we need to find such that . Choose coprime such that doesn't divide it follows that . Further, choosing implies that divides also . The rest is clear.
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