Erdős problem 968
Does the set {n | u n < u (n+1)} have positive lower density?
Sources
FormalConjectures/ErdosProblems/
968.lean
Retained formal statement
Erdős and Prachar proved ∑_{pₙ < x} |u (n+1) - u n| ≍ (log x)^2 (see [ErPr61]).
We encode ∑_{pₙ < x} as a sum over n < Nat.primeCounting' x (the number of primes < x).
(fun x => ∑ n ∈ Finset.Iio x.primeCounting', |Erdos968.u (n + 1) - Erdos968.u n|) =Θ[Filter.atTop] fun x => Real.log ↑x ^ 2SolvedStatement only, no proof