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

Terms

a(0) =1a(1) =3a(2) =9a(3) =25a(4) =66a(5) =168a(6) =416a(7) =1008a(8) =2400a(9) =5632a(10) =13056a(11) =29952a(12) =68096a(13) =153600a(14) =344064a(15) =765952a(16) =1695744a(17) =3735552a(18) =8192000a(19) =17891328a(20) =38928384a(21) =84410368a(22) =182452224a(23) =393216000a(24) =845152256a(25) =1811939328a(26) =3875536896a(27) =8271167488a(28) =17616076800