All open problems
Source labels openChecked July 26, 2026

Erdős ProblemsNumber theory

Erdős Problem 890: A

If ωk(n)\omega_k(n) counts the number of distinct prime factors of nn which are >k>k, then is it true that, for every k1k\geq 1, lim infn0i<kωk(n+i)k?\liminf_{n\to \infty}\sum_{0\leq i < k}\omega_k(n+i)\leq k?

Mathematical statement

If ωk(n)\omega_k(n) counts the number of distinct prime factors of nn which are >k>k, then is it true that, for every k1k\geq 1, lim infn0i<kωk(n+i)k?\liminf_{n\to \infty}\sum_{0\leq i < k}\omega_k(n+i)\leq k?

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_890.parts.a

Canonical source
Complete statement target, proof intentionally absentLean 4
theorem erdos_890.parts.a :    answer(sorry)      k  1, liminf (fun n  (∑ i  range k, (ω_gt k (n + i) : EReal))) atTop  k := 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