Erdős problem 399
Is it true that there are no solutions to n! = x^k ± y^k with x,y,n ∈ ℕ, x*y > 1, and k > 2?
Sources
FormalConjectures/ErdosProblems/
399.lean
Retained formal statement
Erdős and Obláth [ErOb37] proved this is true when and .
∀ {n x y k : ℕ}, x.Coprime y → 1 < x * y → 2 < k → k ≠ 4 → n.factorial ≠ x ^ k + y ^ k ∧ n.factorial + y ^ k ≠ x ^ kSolvedStatement only, no proof