Nat.geomSum_eq

∀ {m : ℕ}, 2 ≤ m → ∀ (n : ℕ), ∑ k ∈ Finset.range n, m ^ k = (m ^ n - 1) / (m - 1)

Value of a geometric sum over the naturals. Note: see geom_sum_mul_add for a formulation that avoids division and subtraction.

Defined in: Mathlib.Algebra.Ring.GeomSum
Cited by: 3 results in Mathlib
Foundations: Depth 70 from the axioms · uses propext, Classical.choice, Quot.sound

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