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

Terms

a(0) =1a(1) =0a(2) =4a(3) =4a(4) =12a(5) =20a(6) =44a(7) =84a(8) =172a(9) =340a(10) =684a(11) =1364a(12) =2732a(13) =5460a(14) =10924a(15) =21844a(16) =43692a(17) =87380a(18) =174764a(19) =349524a(20) =699052a(21) =1398100a(22) =2796204a(23) =5592404a(24) =11184812a(25) =22369620a(26) =44739244a(27) =89478484a(28) =178956972a(29) =357913940