Erdős Problem #844 — Largest Sets with No Squarefree Pairwise Products

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For N∈NN\in\mathbb N, let EN={n∈{1,…,N}:2∣n or n is not squarefree}E_N=\{n\in\{1,\ldots,N\}:2\mid n\text{ or }n\text{ is not squarefree}\}. Is it true that, for every NN, the maximum cardinality of a finite set A⊆{1,…,N}A\subseteq\{1,\ldots,N\} satisfying

∀a,b∈A,ab is not squarefree\forall a,b\in A,\quad ab\text{ is not squarefree}

is ∣EN∣|E_N|?

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