Erdős problem 950
This function was considered by de Bruijn, Erdős, and Turán, who showed that . They gave no proofs, but a proof of the (harder) second claim is given by Gorodetsky here [mathoverflow/508491].
Sources
FormalConjectures/ErdosProblems/
950.lean
Retained formal statement
Is it true that ?
True ↔ Filter.limsup (fun n => ↑(Erdos950.f n)) Filter.atTop = ⊤OpenStatement only, no proof