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

Terms

a(0) =0a(1) =1a(2) =1a(3) =1a(4) =1a(5) =2a(6) =7a(7) =22a(8) =57a(9) =132a(10) =308a(11) =793a(12) =2223a(13) =6328a(14) =17578a(15) =47804a(16) =130169a(17) =360924a(18) =1019084a(19) =2900484a(20) =8252860a(21) =23445510a(22) =66717135a(23) =190750110a(24) =548178735a(25) =1580970612a(26) =4568275692a(27) =13217653582a(28) =38306172442a(29) =111248832992