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Divisors with Balanced Residues Mod 3

Number Theory · CMM 2025 1667
Find the number of odd positive integers $n < 1000$ such that if $S_n$ denotes the set of divisors of $n$, then exactly half of the elements of $S_n$ are divisible by 3, exactly a third of the elements of $S_n$ leave a remainder of 1 upon dividing by 3, and exactly a sixth of the elements of $S_n$ leave a remainder of 2 upon dividing by 3.