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

Terms

a(0) =-1a(1) =1a(2) =1a(3) =1a(4) =4a(5) =3a(6) =11a(7) =10a(8) =29a(9) =31a(10) =76a(11) =91a(12) =199a(13) =258a(14) =521a(15) =715a(16) =1364a(17) =1951a(18) =3571a(19) =5266a(20) =9349a(21) =14103a(22) =24476a(23) =37555a(24) =64079a(25) =99586a(26) =167761a(27) =263251a(28) =439204a(29) =694263