simp only [oddFactors]
z : ℤ
n : ℕ
⊢ oddFactors (z ^ n) = n • oddFactors z
z : ℤ
n : ℕ
⊢ Multiset.filter Odd (UniqueFactorizationMonoid.normalizedFactors (z ^ n)) =
    n • Multiset.filter Odd (UniqueFactorizationMonoid.normalizedFactors z)