Expansion of 1/((1+3*x)*(1-9*x)).

Terms

a(0) =1a(1) =6a(2) =63a(3) =540a(4) =4941a(5) =44226a(6) =398763a(7) =3586680a(8) =32286681a(9) =290560446a(10) =2615103063a(11) =23535750420a(12) =211822285221