lean_workbook_plus_11890

Proved

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

Find the limit of the sequence $(a_n)$ where $a_n = \frac{n^2 + 2n + 1}{n^2 + n}$ as $n$ approaches infinity.

Preamble

import Mathlib.Analysis.Complex.Basic

Formal statement

theorem lean_workbook_plus_11890 (a : ℕ → ℝ) (n : ℕ) : a n = (n^2 + 2*n + 1) / (n^2 + n) → a n ≠ 1 ∨ a n = 1   :=  by sorry

Source