Expansion of x*(1-6*x+7*x^2)/((1-x)*(1+x)*(1-5*x+x^2)).

Terms

a(0) =0a(1) =1a(2) =-1a(3) =2a(4) =5a(5) =31a(6) =144a(7) =697a(8) =3335a(9) =15986a(10) =76589a(11) =366967a(12) =1758240a(13) =8424241a(14) =40362959a(15) =193390562a(16) =926589845a(17) =4439558671a(18) =21271203504a(19) =101916458857a(20) =488311090775