Solve the recurrence 
$$T(1) = 1, T(2) = 1, T(3) = 1,T(n) = 2T(n-1)+n^2, n > 3$$

I have now,
$$T(n) = 2T(n-1)+^2 $$
$$= 2(2T(n-2)+(n-1)^2+n^2$$
$$=4T(n-2)+2(n-1)^2+n^2$$
$$....$$
$$2^iT(n-i)+\sum\_{k=0}^{i-1}=2^{k}(n-k)^2$$
$$2^{n-1}T(1)+\sum\_{k=0}^{n-2}=2^{k}(n-k)^2=2^{n-1}+\sum\_{k=0}^{n-2}2^k(n-k)^2$$

Can anyone help.

The @all