a(n) = a(n-1) + 3*a(n-2) -2*a(n-3) - 2*a(n-4), where a(0) = 0, a(1) = 0, a(2) = -1, a(3) = 1.

Terms

a(0) =0a(1) =0a(2) =-1a(3) =1a(4) =-2a(5) =3a(6) =-3a(7) =8a(8) =-3a(9) =21a(10) =2a(11) =55a(12) =25a(13) =144a(14) =105a(15) =377a(16) =354a(17) =987a(18) =1085a(19) =2584a(20) =3157a(21) =6765a(22) =8898a(23) =17711a(24) =24561a(25) =46368a(26) =66833a(27) =121393a(28) =180034a(29) =317811