Revert transform of 2*x*(1 - x + x^4 - x^5)-x/(1+x).

Terms

a(0) =1a(1) =1a(2) =3a(3) =9a(4) =31a(5) =113a(6) =431a(7) =1697a(8) =6849a(9) =28181a(10) =117787a(11) =498705a(12) =2134499a(13) =9220393a(14) =40146495a(15) =176011777a(16) =776363417a(17) =3442818809a(18) =15340344035a(19) =68645684937a(20) =308365373183