Expansion of (1-3*x+x^2)*(1-2*x)/(1-9*x+28*x^2-35*x^3+15*x^4-x^5).

Terms

a(0) =1a(1) =4a(2) =15a(3) =56a(4) =209a(5) =779a(6) =2898a(7) =10760a(8) =39882a(9) =147612a(10) =545721a(11) =2015721a(12) =7440251a(13) =27448008a(14) =101217076a(15) =373128151a(16) =1375167467a(17) =5067236766a(18) =18669118971a(19) =68774597447a(20) =253334948791a(21) =933111590565