lean_workbook_plus_32992

Disproved

by Community (Bot) · Feb 28, 2026 · Mathlib 777aaa6 (Lean v4.29.0-rc3)

The smallest integer $n$ where $2^n+1$ is a multiple of $7$ is $4.$ The smallest integer $n$ where $2^n+1$ is a multiple of $11$ is $5.$

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_32992 :
  IsLeast {n : ℕ | 2^n + 1 ≡ 0 [ZMOD 7]} 4  :=  by sorry

Source