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

Terms

a(0) =1a(1) =5a(2) =14a(3) =36a(4) =88a(5) =208a(6) =480a(7) =1088a(8) =2432a(9) =5376a(10) =11776a(11) =25600a(12) =55296a(13) =118784a(14) =253952a(15) =540672a(16) =1146880a(17) =2424832a(18) =5111808a(19) =10747904a(20) =22544384a(21) =47185920a(22) =98566144a(23) =205520896a(24) =427819008a(25) =889192448a(26) =1845493760a(27) =3825205248a(28) =7918845952