lean_workbook_plus_27381

Disproved

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

Prove that the function $f: \mathbb{N}^* \rightarrow \mathbb{N}^*$ defined by $f(n) = n^2 + n + 1$ is surjective.

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_27381 : ∀ n : ℕ, n ∈ Set.range (fun n : ℕ => n^2 + n + 1)   :=  by sorry

Source