五、Solve the following recurrence relation:an + 6an-1− 16an-2 = 6, given that a0 = 0 and a1 = 2.

(2) Consider the complete bipartite graphKm,n , where the vertex set is partitioned into two disjoint sets V1 and V2with |V1 | = m and |V2 | = n. Derive the necessary and sufficient conditions for ? and ? such that Km，n contains an Eulerian path but NO Eulerian circuit. (Consider all possible cases for m and n ). (10%)