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

Terms

a(0) =0a(1) =1a(2) =1a(3) =2a(4) =4a(5) =9a(6) =21a(7) =52a(8) =135a(9) =368a(10) =1045a(11) =3068a(12) =9230a(13) =28245a(14) =87414a(15) =272544a(16) =854012a(17) =2685897a(18) =8473107a(19) =26805994a(20) =85045674a(21) =270599945a(22) =863529480a(23) =2763745020a(24) =8870777955a(25) =28550721966a(26) =92128996782a(27) =298004209496a(28) =966085311052