Part I. Sec. 4.2. Prove by mathematical induction that for all n > i-1, 2.
Part II. Sec. 4.4. Consider the alphabet {x, y, z}. Let rn be the number of words of length n in this alphabet that do not contain xz in them.
i) Calculate r0, r1, and r2.
ii) Find a recurrence formula for rn.