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

Terms

a(0) =1a(1) =1a(2) =3a(3) =9a(4) =23a(5) =61a(6) =163a(7) =433a(8) =1151a(9) =3061a(10) =8139a(11) =21641a(12) =57543a(13) =153005a(14) =406835a(15) =1081761a(16) =2876367a(17) =7648165a(18) =20336219a(19) =54073337a(20) =143779223a(21) =382304221a(22) =1016534339a(23) =2702931345a(24) =7187005471a(25) =19110010965a(26) =50812890091a(27) =135109802089a(28) =359252516199a(29) =955240614669