Let a_{0}, a_{1 }::: be the series recursively defined by a_{0} = 1, and an = 3 + a_{n-1} for n ≥ 1.
(a) Compute a_{1}, a_{2}, a_{3} and a_{4}.
(b) Compute a formula for an, n ≥ 0.
(c) Use induction to show that your formula is right.