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

Terms

a(0) =1a(1) =1a(2) =3a(3) =9a(4) =33a(5) =125a(6) =503a(7) =2081a(8) =8849a(9) =38345a(10) =168875a(11) =753401a(12) =3398177a(13) =15469493a(14) =70984559a(15) =327982529a(16) =1524644897a(17) =7125440913a(18) =33459931155a(19) =157794990633a(20) =747021246817