i need to prove this by induction...

N(sub k) is the number of flops needed to compute the determinant of a k x k matrix. N(1) = 0, N(2) = 3, N(3) = 14

Prove: N(k) = ((N(k-1)+2)*k)-1

I set it up so that

N(k-1) = ((N(k-2)+2)*(k-1))-1 for a (k-1) x (k-1) matrix

But now I'm sort of stuck, and am unsure about how to go about reaching the original equation