Erdős problem 442Let Logx:=max{logx,1}\operatorname{Log} x := \max\{\log x, 1\}, Log2x=Log(Logx)\operatorname{Log}_2x = \operatorname{Log} (\operatorname{Log} x), and Log3x=Log(Log(Logx)).\operatorname{Log}_3x = \operatorname{Log}(\operatorname{Log}(\operatorname{Log} x)). Is it true that if A⊆NA\subseteq\mathbb{N} is such that 1Log2x∑n∈A:n≤x1n→∞ \frac{1}{\operatorname{Log}_2 x} \sum_{n\in A: n\leq x} \frac{1}{n}\to\infty then (∑n∈A:n≤x1n)2∑n,m∈A:n<m≤x1lcm(n,m)→∞ \left(\sum_{n\in A: n\leq x} \frac{1}{n}\right)^2 \sum_{n, m \in A: n < m \leq x} \frac{1}{\operatorname{lcm}(n, m)}\to\infty as x→∞x\to\infty?WorkspaceContinue locallyOpen sourceSign in to contributeOpen this exact Problem, source revision, and authority Repository in Workbench. This handoff does not clone, switch, upload, or execute anything.FilesErdős problem 4423 retained source recordsCanvaspublic previewSource#442→ResultNone→Checks0