Source labels openChecked July 26, 2026

Erdős Problem 406: One Two

If we only allow the digits $1$ and $2$ then $2^{15}$ seems to be the largest such power of $2$ .

Number theory AMS 11

Mathematical statement

If we only allow the digits $1$ and $2$ then $2^{15}$ seems to be the largest such power of $2$ .

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_406.variants.one_two

Canonical source

Complete statement target, proof intentionally absentLean 4

theorem erdos_406.variants.one_two :    IsGreatest { n | n.isPowerOfTwo ∧ Nat.digits 3 n ⊆ [1, 2] } (2 ^ 15) := 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

Pinned Formal Conjectures sourceformalization erdosproblems.com/406background