Expansion of (1+x)*(1+2*x)*(1-x)/(1-5*x^2+5*x^4).

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =15a(5) =30a(6) =55a(7) =110a(8) =200a(9) =400a(10) =725a(11) =1450a(12) =2625a(13) =5250a(14) =9500a(15) =19000a(16) =34375a(17) =68750a(18) =124375a(19) =248750a(20) =450000a(21) =900000a(22) =1628125a(23) =3256250a(24) =5890625a(25) =11781250a(26) =21312500a(27) =42625000a(28) =77109375a(29) =154218750