Reversion of y - y^2 - y^3 - y^4 + y^5.

Terms

a(0) =0a(1) =1a(2) =1a(3) =3a(4) =11a(5) =43a(6) =182a(7) =806a(8) =3687a(9) =17297a(10) =82753a(11) =402207a(12) =1980407a(13) =9857715a(14) =49522564a(15) =250768564a(16) =1278600022a(17) =6558731904a(18) =33823966611a(19) =175264755549a(20) =912043488146