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

Terms

a(0) =1a(1) =1a(2) =-1a(3) =-4a(4) =-5a(5) =1a(6) =9a(7) =11a(8) =-4a(9) =-25a(10) =-31a(11) =9a(12) =64a(13) =79a(14) =-25a(15) =-169a(16) =-209a(17) =64a(18) =441a(19) =545a(20) =-169a(21) =-1156a(22) =-1429a(23) =441a(24) =3025a(25) =3739a(26) =-1156a(27) =-7921a(28) =-9791a(29) =3025