Expansion of 1/(sqrt(1-4*x) + sqrt(1-2*x-3*x^2) - 1).

Terms

a(0) =1a(1) =3a(2) =13a(3) =57a(4) =255a(5) =1149a(6) =5201a(7) =23607a(8) =107345a(9) =488721a(10) =2227007a(11) =10154511a(12) =46323507a(13) =211396611a(14) =964966149a(15) =4405717137a(16) =20118308687a(17) =91880092029a(18) =419657355725