Skip to content

Erdős problem 749

Let ϵ>0\epsilon>0. Does there exist A⊆NA\subseteq \mathbb{N} such that the lower density of A+AA+A is at least 1−ϵ1-\epsilon and yet 1A∗1A(n)≪ϵ11_A\ast 1_A(n) \ll_\epsilon 1 for all nn?

Sources

The source's own material, retained exactly.

1 retained statement36c6d0fef71a

Open selected source

FormalConjectures/ErdosProblems/

749.lean

Retained formal statement1 of 1

Let ϵ>0\epsilon>0. Does there exist A⊆NA\subseteq \mathbb{N} such that the lower density of A+AA+A is at least 1−ϵ1-\epsilon and yet 1A∗1A(n)≪ϵ11_A\ast 1_A(n) \ll_\epsilon 1 for all nn?

FormalConjectures/ErdosProblems/749.leanErdos749.erdos_7492 linesExact file
True ↔  ∀ ε > 0, ∃ A, 1 - ε ≤ (A + A).lowerDensity ∧ (Nat.cast ∘ AdditiveCombinatorics.sumRep A) =O[Filter.atTop] fun n => 1
OpenStatement only, no proof