Consider the sequence defined by b0 = 0, b1 = 1, b2 = 2, and bn = bn−1 + 2bn−2 − 2bn−3
for n ≥ 3. Determine the values of b3, b4, b5, b6, and a closed form expression for bn. (You
will need to think about how to appropriately extend the type of closed form expression
given above.)