Nat.eq_sq_add_sq_iff_eq_sq_mul

∀ {n : ℕ}, (∃ x y, n = x ^ 2 + y ^ 2) ↔ ∃ a b, n = a ^ 2 * b ∧ IsSquare (-1)

A natural number n is a sum of two squares if and only if n = a^2 * b with natural numbers a and b such that -1 is a square modulo b.

Defined in: Mathlib.NumberTheory.SumTwoSquares
Cited by: 1 results in Mathlib
Foundations: Depth 152 from the axioms · uses propext, Classical.choice, Quot.sound

Around this declaration

Dashed lines are statement dependencies; solid lines are citations in proofs.

Mathlib declarations this one mentions in its statement or cites explicitly in its proof. Plumbing is filtered out.

Results whose statement or proof uses this declaration.