G.f.: A(x) = F(x*G(x)^2) where F(x) = G(x/F(x)) = 1 + x*F(x)^2 is the g.f. of A000108 (Catalan) and G(x) = F(x*G(x)) = 1 + x*G(x)^3 is the g.f. of A001764.

A153295

G.f.: A(x) = F(x*G(x)^2) where F(x) = G(x/F(x)) = 1 + x*F(x)^2 is the g.f. of A000108 (Catalan) and G(x) = F(x*G(x)) = 1 + x*G(x)^3 is the g.f. of A001764.

Terms

    a(0) =1a(1) =1a(2) =4a(3) =20a(4) =110a(5) =638a(6) =3828a(7) =23515a(8) =146972a(9) =930869a(10) =5958094a(11) =38462190a(12) =250054804a(13) =1635421543a(14) =10750864640a(15) =70987129653a(16) =470542935654

External references