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Source labels openChecked July 26, 2026

Erdős ProblemsNumber theory

Erdős Problem 348

For what values of 0m<n0 \leq m < n is there a complete sequence A={a1a2}A = \{a_1 \leq a_2 \leq \cdots\} of integers such that 1. AA remains complete after removing any mm elements, but 2. AA is not complete after removing any nn elements.

Mathematical statement

For what values of 0m<n0 \leq m < n is there a complete sequence A={a1a2}A = \{a_1 \leq a_2 \leq \cdots\} of integers such that

  1. AA remains complete after removing any mm elements, but
  2. AA is not complete after removing any nn elements.

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_348

Canonical source
Complete statement target, proof intentionally absentLean 4
theorem erdos_348 :    { (m, n) | (m) (n) (_ : m < n) (a :   ) (_ : Monotone a)      (_ :  s, s.card = m  IsAddComplete (Set.range (Function.updateFinset a s 0)))        (_ :  t, t.card = n  ¬IsAddComplete (Set.range (Function.updateFinset a t 0))) } =    answer(sorry) := 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