G.f. satisfies: A(x) = Sum_{n>=0} x^n * (A(x) + x^n)^n.

Terms

a(0) =1a(1) =1a(2) =3a(3) =6a(4) =19a(5) =56a(6) =186a(7) =615a(8) =2127a(9) =7467a(10) =26720a(11) =96801a(12) =354901a(13) =1313293a(14) =4900266a(15) =18413166a(16) =69620351a(17) =264673536a(18) =1011100541a(19) =3879382837a(20) =14942671683a(21) =57760251344a(22) =223988614094a(23) =871159201568