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

Terms

a(0) =1a(1) =2a(2) =8a(3) =31a(4) =115a(5) =431a(6) =1616a(7) =6055a(8) =22690a(9) =85028a(10) =318629a(11) =1194013a(12) =4474381a(13) =16767056a(14) =62831969a(15) =235453162a(16) =882324592a(17) =3306376007a(18) =12390136691a(19) =46430135863a(20) =173989808992a(21) =652000108775