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

Terms

a(0) =1a(1) =2a(2) =6a(3) =15a(4) =36a(5) =84a(6) =192a(7) =432a(8) =960a(9) =2112a(10) =4608a(11) =9984a(12) =21504a(13) =46080a(14) =98304a(15) =208896a(16) =442368a(17) =933888a(18) =1966080a(19) =4128768a(20) =8650752a(21) =18087936a(22) =37748736a(23) =78643200a(24) =163577856a(25) =339738624a(26) =704643072a(27) =1459617792a(28) =3019898880a(29) =6241124352