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Erdős problem 950

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This function was considered by de Bruijn, Erdős, and Turán, who showed that ∑n<xf(n)∼∑n<xf(n)2∼x\sum_{n<x}f(n)\sim \sum_{n<x}f(n)^2\sim x. They gave no proofs, but a proof of the (harder) second claim is given by Gorodetsky here [mathoverflow/508491].

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The source's own material, retained exactly.

7 retained statements36c6d0fef71a

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FormalConjectures/ErdosProblems/

950.lean

Retained formal statement2 of 7

Is it true that lim sup⁡f(n)=∞\limsup f(n)=\infty?

FormalConjectures/ErdosProblems/950.leanErdos950.erdos_950.parts.ii1 lineExact file
True ↔ Filter.limsup (fun n => ↑(Erdos950.f n)) Filter.atTop = ⊤
OpenStatement only, no proof