2. (2.4.9) Find the first five terms of each of the following recurrence relations: (a) an = 6an-1, where ao = 2 (b) an = a*-1, where ai = 2 (c) an = an-1 + 3an-2, where ao = 1 and ai = 2 (d) an = an-1 +an-3, where ao = 1, a1 = 2, and a2 = = 0