G.f. satisfies: A(x) = 1 + x*A(x)^2 + x^2/A(x).

Terms

a(0) =1a(1) =1a(2) =3a(3) =6a(4) =16a(5) =52a(6) =169a(7) =556a(8) =1902a(9) =6667a(10) =23665a(11) =85062a(12) =309444a(13) =1136400a(14) =4205944a(15) =15675690a(16) =58785582a(17) =221644054a(18) =839692735a(19) =3194875093a(20) =12203132521a(21) =46774765206a(22) =179861164503a(23) =693632630011