lean_workbook_plus_11003

Proved

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

Prove that there exists infinitely many positive integers n such that $4n^{2}+1$ is divisible both by 5 and 13.

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_11003 : ∃ n : ℕ, 5 ∣ 4 * n ^ 2 + 1 ∧ 13 ∣ 4 * n ^ 2 + 1   :=  by sorry

Source