G.f. satisfies: A(x) = Sum_{n>=0} x^n / Product_{k=1..n} (x + A(-x)^k).

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =2a(6) =5a(7) =7a(8) =23a(9) =48a(10) =190a(11) =469a(12) =2076a(13) =5613a(14) =27112a(15) =80004a(16) =415821a(17) =1332560a(18) =7380671a(19) =25483465a(20) =149401274a(21) =552137511a(22) =3408722899a(23) =13414205244a(24) =86845091349a(25) =362317409552