a(n) = -a(n-1)+4*a(n-2)+4*a(n-3)-a(n-4)-a(n-5).

Terms

a(0) =0a(1) =1a(2) =1a(3) =2a(4) =3a(5) =8a(6) =10a(7) =31a(8) =36a(9) =117a(10) =133a(11) =438a(12) =495a(13) =1636a(14) =1846a(15) =6107a(16) =6888a(17) =22793a(18) =25705a(19) =85066a(20) =95931a(21) =317472a(22) =358018a(23) =1184823a(24) =1336140a(25) =4421821a(26) =4986541a(27) =16502462a(28) =18610023a(29) =61588028