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

Terms

a(0) =0a(1) =1a(2) =1a(3) =5a(4) =12a(5) =38a(6) =107a(7) =316a(8) =915a(9) =2671a(10) =7771a(11) =22640a(12) =65922a(13) =191993a(14) =559112a(15) =1628281a(16) =4741905a(17) =13809541a(18) =40216516a(19) =117119750a(20) =341079507a(21) =993301748a(22) =2892722267a(23) =8424270271a(24) =24533405595a(25) =71446899736a(26) =208069745986a(27) =605946785585