Expansion of (1/(1-x))(1+2x/(1-x+sqrt(1-2x-3x^2))).

Terms

a(0) =1a(1) =2a(2) =3a(3) =5a(4) =9a(5) =18a(6) =39a(7) =90a(8) =217a(9) =540a(10) =1375a(11) =3563a(12) =9361a(13) =24872a(14) =66707a(15) =180341a(16) =490913a(17) =1344380a(18) =3701159a(19) =10237541a(20) =28436825a(21) =79288844a(22) =221836403a(23) =622599626a(24) =1752360041a(25) =4945087838a(26) =13988490339a(27) =39658308815a(28) =112666081617