Find the solution of the recurrence relation $\displaystyle a_{n} = 2a_{n-1} + 2n^2 $ with initial condition a1 = 4.

As this is the linear non-homogeneous recurrence relation which has a general solution in the form of an = h(n) + p(n).

I tried solving the h(n), homogeneous part first $\displaystyle a_{n} = 2a_{n-1} $.

I got $\displaystyle h(n) = A2^n $ , for some constant A.

But now i am confused about the particular solution p(n), how do i find that? Someone please help.