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Problems / erdos-1094 / erdos-1094--h2--h1--h4--h1--h1

the thin strip with n prime and coprime to k

erdos-1094--h2--h1--h4--h1--h1

open

Hole h_cop of erdos-1094--h2--h1--h4--h1 (split by 20261015T145300Z-t1015c-a06-partial.lean).

$\displaystyle \exists K\in\mathbb{N}\ \forall n,k\in\mathbb{N}:\quad 0<k,\ \ k^2\le n,\ \ n<k\bigl(k+3k^{21/40}\bigr),\ \ k\lfloor n/k\rfloor\mid k!,\ \ \operatorname{minFac}\tbinom{n}{k}>\lfloor n/k\rfloor,\ \ n\text{ prime},\ \ \gcd(n,k)=1\ \Longrightarrow\ k\le K$

Only finitely many $k$ admit an $n$ in the strip $k^2\le n<k(k+3k^{21/40})$ (the upper bound taken over the reals, with $21/40$ a real exponent) such that $k\lfloor n/k\rfloor$ divides $k!$, the least prime factor of $\binom{n}{k}$ exceeds $\lfloor n/k\rfloor$, and $n$ is prime with $\gcd(n,k)=1$. Lean conventions: n / k is floor division, $n/\gcd(n,k)$ is natural-number division, exact here since the gcd divides $n$, and Nat.minFac is the least prime factor (1 at 1, 2 at 0).

unverified · history

Lean
theorem erdos_1094__h2__h1__h4__h1__h1 : ∃ (K : ℕ),
  ∀ (n k : ℕ),
    (0 : ℕ) < k →
      k * k ≤ n →
        (↑n : ℝ) < (↑k : ℝ) * ((↑k : ℝ) + (3 : ℝ) * (↑k : ℝ) ^ (21 / 40 : ℝ)) →
          k * (n / k) ∣ k.factorial → (n.choose k).minFac > n / k → Nat.Prime n → n.gcd k = (1 : ℕ) → k ≤ K := by
  sorry
Why does it end in sorry?

A statement is written := by sorry: the sorry holds the place of a proof, because a statement file only says what is claimed. A proof the gate checked is its own file, Proof.lean. How to read a proof page →

How it is being proved

Open. A direct proof closes it.

What is known

Work on it

Work on this statement →

How to contribute → · Pull requests in flight ↗ · See it in the problem’s graph →

Record

Statement: the Lean file and its words (1 version)

Statement not audited — only a problem’s root statement is audited for fidelity (D-9); the kernel checks a proof against this Lean as written.

import Mathlib
import Nodes.«erdos-1094--h2--h1--h4--h1--h1».Context

open scoped Nat

/-! Hole `h_cop` of a merged partial proof, as a node (D-12 #5, D-29).
Statement generated by the gate from the assembly; immutable (D-3). -/

theorem erdos_1094__h2__h1__h4__h1__h1 : ∃ (K : ℕ),
  ∀ (n k : ℕ),
    (0 : ℕ) < k →
      k * k ≤ n →
        (↑n : ℝ) < (↑k : ℝ) * ((↑k : ℝ) + (3 : ℝ) * (↑k : ℝ) ^ (21 / 40 : ℝ)) →
          k * (n / k) ∣ k.factorial → (n.choose k).minFac > n / k → Nat.Prime n → n.gcd k = (1 : ℕ) → k ≤ K := by
  sorry

A statement is written := by sorry: the sorry holds the place of a proof, because a statement file only says what is claimed. A proof the gate checked is its own file, Proof.lean. How to read a proof page →

In words, unverified — what this statement says; written by f29-words, drafted with Claude Fable 5.1 (claude-fable-5-1), 2026-10-18; no one has read it against the Lean and signed it.

Draft · drafted, by the model named above

$\displaystyle \exists K\in\mathbb{N}\ \forall n,k\in\mathbb{N}:\quad 0<k,\ \ k^2\le n,\ \ n<k\bigl(k+3k^{21/40}\bigr),\ \ k\lfloor n/k\rfloor\mid k!,\ \ \operatorname{minFac}\tbinom{n}{k}>\lfloor n/k\rfloor,\ \ n\text{ prime},\ \ \gcd(n,k)=1\ \Longrightarrow\ k\le K$

Only finitely many $k$ admit an $n$ in the strip $k^2\le n<k(k+3k^{21/40})$ (the upper bound taken over the reals, with $21/40$ a real exponent) such that $k\lfloor n/k\rfloor$ divides $k!$, the least prime factor of $\binom{n}{k}$ exceeds $\lfloor n/k\rfloor$, and $n$ is prime with $\gcd(n,k)=1$. Lean conventions: n / k is floor division, $n/\gcd(n,k)$ is natural-number division, exact here since the gcd divides $n$, and Nat.minFac is the least prime factor (1 at 1, 2 at 0).

Rendered from gloss/b61dd4516232….md · Improve these words →

Rendered from targets/erdos-1094/nodes/erdos-1094--h2--h1--h4--h1--h1/Statement.lean. Origin: compiler-derived.

Witness

Not checked — no run on this page records step 7 passing for it.

Witness.lean — filled; the gate checks it at step 7 of every submission against this statement. Rendered from targets/erdos-1094/nodes/erdos-1094--h2--h1--h4--h1--h1/Witness.lean, sha256 afa146693f9c.
import Mathlib
import Nodes.«erdos-1094--h2--h1--h4--h1--h1».Context
open scoped Nat

/-! The witness slot for a hole (D-29, F07-R6). Replace `sorry` with an instance
satisfying this statement's hypotheses; until then the node is blocked. -/

theorem witness : True := trivial

No gloss yet: no one has written in words what this witness says (D-3 v3.30); the Lean above is the witness. How to write one →

How to read this page

No explainer yet. An explainer is a merged proof written as a journal would print it, so there is nothing to explain until this statement is proved (D-3).

How to read a statement’s page →