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

Terms

a(0) =0a(1) =1a(2) =1a(3) =2a(4) =4a(5) =8a(6) =14a(7) =16a(8) =-21a(9) =-242a(10) =-1166a(11) =-4472a(12) =-15132a(13) =-46508a(14) =-130016a(15) =-323000a(16) =-660535a(17) =-786714a(18) =1789952a(19) =18546464a(20) =93845290a(21) =380532240a(22) =1355983860a(23) =4363436280a(24) =12688926510a(25) =32530717752a(26) =67666586472a(27) =76255301640a(28) =-240266135872