Solve a0 = 0, a1 = 1 and an = an−1 + an−2 + 2n , for n ≥ 2. Hints: This one involves a lot more algebra than the problems above. Solving the homogeneous problem will involve using the quadratic formula. The characteristic roots turn out to be 1 ± √ 5 2 (but show the work!). For a particular solution, try an = A2 n . You should find A = 4 (but show the work!). Put those two pieces together to write down the general solution an = A( (1 + √ 5 )/2 )^n + B( (1 − √ 5)/ 2 )^n + 4(2^n ) and the determine the values for A and B by using the two initial conditions, a0 = 0 and a1 = 1. The necessary arithmetic will be somewhat complicated, but not impossible.