Using the technique of generating functions, solve the following recurrence relations. (i) an - 7an-1 + 10an-2 = 0 for n > 2, where ao = 1 and a; = 7. (ii) an - San-1 + 21an-2 - 18an-3 = 0 for n > 3, where do = 0,01 = 2 and az = -1. n (iii) On - 2an-1-n=0 for n > 1, where do = 0. -