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

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =3a(5) =13a(6) =43a(7) =113a(8) =273a(9) =725a(10) =2245a(11) =7305a(12) =22875a(13) =68545a(14) =204247a(15) =626177a(16) =1977377a(17) =6301577a(18) =19965657a(19) =62913409a(20) =198797059a(21) =633412869a(22) =2032810979a(23) =6543426769a(24) =21071181585a(25) =67905492605a(26) =219347606365a(27) =710732629705