Apart from the leading term, a(n) = Catalan(n-1)*4^(n-1).

A052704

Apart from the leading term, a(n) = Catalan(n-1)*4^(n-1).

Terms

    a(0) =0a(1) =1a(2) =4a(3) =32a(4) =320a(5) =3584a(6) =43008a(7) =540672a(8) =7028736a(9) =93716480a(10) =1274544128a(11) =17611882496a(12) =246566354944

External references