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Erdős problem 245

Let A⊆NA\subseteq\mathbb{N} be an infinite set such that ∣A∩{1,...,N}∣=o(N)|A\cap \{1, ..., N\}| = o(N). Is it true that lim sup⁡N→∞∣(A+A)∩{1,...,N}∣∣A∩{1,...,N}∣≥3? \limsup_{N\to\infty}\frac{|(A + A)\cap \{1, ..., N\}|}{|A \cap \{1, ..., N\}|} \geq 3?

No current result

No reviewed Result is current in Vela Mathematics Program. Retained source material is shown below.

Retained declaration

FormalConjectures/ErdosProblems/245.lean

Formal Conjectures

FormalConjectures/ErdosProblems/245.leanErdos245.erdos_2455 linesExact file
True ↔  ∀ (A : Set ℕ),    A.Infinite →      Filter.Tendsto (fun N => ↑(A ∩ Set.Icc 1 ⌊N⌋₊).ncard / N) Filter.atTop (nhds 0) →        3 ≤ Filter.limsup (fun N => ↑((A + A) ∩ Set.Icc 1 ⌊N⌋₊).ncard / ↑(A ∩ Set.Icc 1 ⌊N⌋₊).ncard) Filter.atTop
SolvedStatement only, no proof

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