Expansion of g.f. 1/((1-2*x)*(1-7*x)).

Terms

a(0) =1a(1) =9a(2) =67a(3) =477a(4) =3355a(5) =23517a(6) =164683a(7) =1152909a(8) =8070619a(9) =56494845a(10) =395464939a(11) =2768256621a(12) =19377800443a(13) =135644611293a(14) =949512295435