G.f.: A(x) = exp( Sum_{n>=1} A((-1)^n*x)^n * x^n/n ).

Terms

a(0) =1a(1) =1a(2) =0a(3) =1a(4) =0a(5) =2a(6) =2a(7) =9a(8) =8a(9) =38a(10) =28a(11) =154a(12) =126a(13) =676a(14) =602a(15) =3129a(16) =2816a(17) =14718a(18) =13384a(19) =70334a(20) =65204a(21) =342108a(22) =321788a(23) =1686698a(24) =1602214a(25) =8402492a(26) =8051652a(27) =42239764a(28) =40797750a(29) =214045640