Revert transform of 2*x*(1 - x + x^6)-x/(1+x).

Terms

a(0) =1a(1) =1a(2) =3a(3) =9a(4) =33a(5) =125a(6) =501a(7) =2063a(8) =8719a(9) =37531a(10) =164093a(11) =726491a(12) =3250743a(13) =14676923a(14) =66780835a(15) =305908709a(16) =1409609741a(17) =6529455069a(18) =30386379215a(19) =142002499261a(20) =666116180157