Expansion of g.f.: x/(1 - 9*x - x^2).

Terms

a(0) =0a(1) =1a(2) =9a(3) =82a(4) =747a(5) =6805a(6) =61992a(7) =564733a(8) =5144589a(9) =46866034a(10) =426938895a(11) =3889316089a(12) =35430783696a(13) =322766369353