simp only [evenFactorExp]
z : ℤ
n : ℕ
⊢ evenFactorExp (z ^ n) = n * evenFactorExp z
z : ℤ
n : ℕ
⊢ Multiset.count 2 (UniqueFactorizationMonoid.normalizedFactors (z ^ n)) =
    n * Multiset.count 2 (UniqueFactorizationMonoid.normalizedFactors z)