Erdős problem 844 · problems.science

Let $A\subseteq \{1,\ldots,N\}$ be such that, for all $a,b\in A$ , the product $ab$ is not squarefree.

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FormalConjectures/ErdosProblems/844.lean

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FormalConjectures/ErdosProblems/844.leanErdos844.erdos_8444 linesExact file

1True ↔2  ∀ (N : ℕ),3    IsGreatest {k | ∃ A ⊆ Finset.Icc 1 N, (∀ a ∈ A, ∀ b ∈ A, ¬Squarefree (a * b)) ∧ A.card = k}4      (Erdos844.evenOrOddNonSquarefree N).card

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Jayyhk Erdős Leanjayyhk:erdos:844
PLBY Lean proofsErdosProblems.Erdos844

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Erdős AI contributions wiki · 26 Apr, 2026
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