a(n) = Product_{k=1..n} binomial(2*k,k).

A007685

a(n) = Product_{k=1..n} binomial(2*k,k).

Terms

    a(0) =1a(1) =2a(2) =12a(3) =240a(4) =16800a(5) =4233600a(6) =3911846400

External references