/- Copyright 2025 The Formal Conjectures Authors. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at https://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. -/ import FormalConjecturesUtil

Erdős Problem 1094

Reference: erdosproblems.com/1094

namespace Erdos1094 open scoped Nat

For all $n\ge 2k$ the least prime factor of $\binom{n}{k}$ is $\le\max(n/k,k)$, with only finitely many exceptions.

@[category research open, AMS 11] theorem declaration uses 'sorry'erdos_1094 : {(n, k) : × | 0 < k 2 * k n (n.choose k).minFac > max (n / k) k}.Finite := {(n, k) | 0 < k 2 * k n (n.choose k).minFac > max (n / k) k}.Finite All goals completed! 🐙 end Erdos1094