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

Terms

a(0) =1a(1) =1a(2) =3a(3) =8a(4) =23a(5) =66a(6) =192a(7) =561a(8) =1647a(9) =4850a(10) =14318a(11) =42351a(12) =125468a(13) =372191a(14) =1105275a(15) =3285288a(16) =9772767a(17) =29090826a(18) =86646486a(19) =258208671a(20) =769820418a(21) =2296067565a(22) =6850744365a(23) =20447143866a(24) =61045757604a(25) =182303186391a(26) =544550917797