All open problems
Source labels openChecked July 26, 2026

OEISNumber theory

Smallest number k such that kn + 1 is prime

A stronger conjecture: for every n there exists a number k<1+n0.75k < 1 + n^{0.75} such that nk+1nk + 1 is a prime.

Mathematical statement

A stronger conjecture: for every n there exists a number k<1+n0.75k < 1 + n^{0.75} such that nk+1nk + 1 is a prime.

Statement source: OEIS statement material

Statement terms: CC-BY-SA-4.0

Attributed source material. Reuse must follow the linked attribution and share-alike terms.

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

exists_k_stronger

Canonical source
Complete statement target, proof intentionally absentLean 4
theorem exists_k_stronger {n : } (hn : 0 < n) :  k : ,    k < 1 + (Real.nthRoot 4 n) ^ 3  (n * k + 1).Prime := 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