G.f. satisfies: A(x) = x + A( A(x)^2 - A(x)^5 ).

Terms

a(0) =1a(1) =1a(2) =2a(3) =6a(4) =19a(5) =65a(6) =234a(7) =873a(8) =3346a(9) =13099a(10) =52154a(11) =210541a(12) =859768a(13) =3545263a(14) =14741148a(15) =61736903a(16) =260192880a(17) =1102704585a(18) =4696416190a(19) =20090502706a(20) =86285786519a(21) =371917832707