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

Terms

a(0) =1a(1) =1a(2) =3a(3) =9a(4) =28a(5) =88a(6) =284a(7) =931a(8) =3109a(9) =10532a(10) =36162a(11) =125546a(12) =440201a(13) =1556519a(14) =5544715a(15) =19879791a(16) =71685522a(17) =259809731a(18) =945913555a(19) =3457947627a(20) =12687782600a(21) =46709518473a(22) =172484216742a(23) =638712762962