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

Terms

a(0) =0a(1) =0a(2) =1a(3) =4a(4) =20a(5) =97a(6) =472a(7) =2296a(8) =11169a(9) =54332a(10) =264300a(11) =1285697a(12) =6254320a(13) =30424368a(14) =148000449a(15) =719953588a(16) =3502240516a(17) =17036776865a(18) =82876023112a(19) =403153440424