Expansion of (1-x)/(1-2x-4x^2+4x^3).

Terms

a(0) =1a(1) =1a(2) =6a(3) =12a(4) =44a(5) =112a(6) =352a(7) =976a(8) =2912a(9) =8320a(10) =24384a(11) =70400a(12) =205056a(13) =594176a(14) =1726976a(15) =5010432a(16) =14552064a(17) =42237952a(18) =122642432a(19) =356028416a(20) =1033674752a(21) =3000893440a(22) =8712372224a(23) =25293619200a(24) =73433153536a(25) =213191294976a(26) =618940727296