G.f.: A(x) = F(x*G(x)^3)^2 = F(G(x)-1)^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.
A153298
G.f.: A(x) = F(x*G(x)^3)^2 = F(G(x)-1)^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) =2a(2) =11a(3) =68a(4) =443a(5) =2974a(6) =20361a(7) =141356a(8) =991738a(9) =7015814a(10) =49967892a(11) =357896120a(12) =2575844046a(13) =18616823352a(14) =135051785186a(15) =982949932092
External references
- oeis: A153298