All open problems
Source labels openChecked July 26, 2026

Erdős ProblemsNumber theory

Erdős Problem 218: Infinite Equal Prime Gap

There are infintely many indices nn such that the prime gap at nn is equal to the prime gap at n+1n+1. This is equivalent to the existence of infinitely many arithmetic progressions of length 33, see erdos_141.variants.infinite_three.

Mathematical statement

There are infintely many indices nn such that the prime gap at nn is equal to the prime gap at n+1n+1. This is equivalent to the existence of infinitely many arithmetic progressions of length 33, see erdos_141.variants.infinite_three.

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_218.variants.infinite_equal_prime_gap

Canonical source
Complete statement target, proof intentionally absentLean 4
theorem erdos_218.variants.infinite_equal_prime_gap : {n | primeGap n = primeGap (n + 1)}.Infinite := 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