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Source labels openChecked July 26, 2026

Erdős ProblemsNumber theory

Erdős Problem 677

Denote by M(n,k)M(n, k) the least common multiple of the finite set {n+1,,n+k}\{n+1, \dotsc, n+k\}. Is it true that for all mn+km \geq n + k, we get M(m,k)M(n,k)M(m, k) \neq M(n, k)?

Mathematical statement

Denote by M(n,k)M(n, k) the least common multiple of the finite set {n+1,,n+k}\{n+1, \dotsc, n+k\}. Is it true that for all mn+km \geq n + k, we get M(m,k)M(n,k)M(m, k) \neq M(n, 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_677

Canonical source
Complete statement target, proof intentionally absentLean 4
theorem erdos_677 :     (m n k : ), k > 0  m  n + k  lcmInterval m k  lcmInterval n 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