2.38 if b = 0, k = 0, 1, 2, 3 a 1, a 2, a 4, a 8 else if b = a, k = 0, 1, 2, 3 a 2, a 3, a 5, a 9 so the result is 1, 2, 3, 4, 5, 8, 9