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

Terms

a(0) =1a(1) =3a(2) =10a(3) =35a(4) =126a(5) =461a(6) =1702a(7) =6315a(8) =23494a(9) =87533a(10) =326382a(11) =1217483a(12) =4542526a(13) =16950573a(14) =63255670a(15) =236063915a(16) =880983606a(17) =3287837741a(18) =12270301822a(19) =45793238475a(20) =170902389934a(21) =637815796973