Here is another one using a leaky ReLU recurrent net: x(n) = C(1) + C(2)*min(x(n-1),0)+(C(2)+C(3))*max(x(n-1),0) + C(4)*min(x(n-2),0)+(C(4)+C(5))*max(x(n-2),0) + C(6)*min(x(n-3),0)+(C(6)+C(7))*max(x(n-3),0)
C = [-0.3948 -0.0697 -0.1657 -0.2916 0.7402 0.8650 0.0673]