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

Terms

a(0) =1a(1) =-3a(2) =7a(3) =-16a(4) =36a(5) =-81a(6) =182a(7) =-409a(8) =919a(9) =-2065a(10) =4640a(11) =-10426a(12) =23427a(13) =-52640a(14) =118281a(15) =-265775a(16) =597191a(17) =-1341876a(18) =3015168a(19) =-6775021a(20) =15223334a(21) =-34206521a(22) =76861355a(23) =-172705897a(24) =388066628a(25) =-871977798a(26) =1959316327a(27) =-4402543824a(28) =9892426177a(29) =-22228079851