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) =1959316327