All open problems
Source labels openChecked July 26, 2026

Erdős ProblemsNumber theory

Erdős Problem 208: I

Let s1<s2<s_1 < s_2 < \dots be the sequence of squarefree numbers. Is it true that for any ϵ>0\epsilon > 0 and large nn, sn+1snϵsnϵs_{n+1} - s_n \ll_\epsilon s_n^\epsilon?

Mathematical statement

Let s1<s2<s_1 < s_2 < \dots be the sequence of squarefree numbers. Is it true that for any ϵ>0\epsilon > 0 and large nn, sn+1snϵsnϵs_{n+1} - s_n \ll_\epsilon s_n^\epsilon?

Statement source: Erdős Problems statement material

Statement terms: Source-specific

Source-specific terms. Therefore does not assert reuse rights beyond attributed display.

Statement artifacts, not proofs

These records expose exact Lean propositions and statement-only wrappers. Defining a proposition does not supply a proof of it. A placeholder-bearing target also contains no proof. Elaboration checks syntax and types; it does not certify that a formalization perfectly captures every nuance of the informal problem.

Pinned Lean formulation 1

erdos_208.parts.i

Canonical source
Complete statement target, proof intentionally absentLean 4
theorem erdos_208.parts.i : answer(sorry)      ε > (0 : ), (fun n => (s (n + 1) - s n : )) =O[atTop] (fun n => (s n : )^ε) := by sorry /--Let $s_1 < s_2 < \dots$ be the sequence of squarefree numbers. Is it true that$s_{n + 1} - s_n \le (1 + o(1)) \cdot (\pi^2 / 6) \cdot \log (s_n) / \log (\log (s_n))$?-/@[category research open, AMS 11]theorem erdos_208.parts.ii : answer(sorry)   (c :   ), (c =o[atTop] (1 :   ))  ᶠ n in atTop,      s (n + 1) - s n  (1 + (c n)) *^2 / 6) * log (s n) / log (log (s n)) := by  sorry
Statement source
Formal Conjectures
Lean version
v4.27.0
Placeholder
Present; no proof artifact
Source evidence
Pinned source index
Fidelity review
Community formulation

References