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

Terms

a(0) =1a(1) =3a(2) =7a(3) =17a(4) =43a(5) =113a(6) =305a(7) =839a(8) =2339a(9) =6585a(10) =18677a(11) =53283a(12) =152725a(13) =439455a(14) =1268623a(15) =3672457a(16) =10656691a(17) =30988249a(18) =90275989a(19) =263425651a(20) =769801873a(21) =2252531971a(22) =6599018227a(23) =19353381877a(24) =56814946381a(25) =166940119063a(26) =490930181515