Tribonacci Exception Finder

Tribonacci Sequence: a₀ = 0, a₁ = 1, a₂ = 1, aₙ = aₙ₋₁ + aₙ₋₂ + aₙ₋₃

Conjecture: For all n ≥ 1, ∃ N with 1 ≤ N ≤ (bound × n) such that n | aₙ

Exception: A value of n where NO such N exists within the bound