a(n) = denominator(2^(2*n-2)/factorial(2*n-1)).

A156769

a(n) = denominator(2^(2*n-2)/factorial(2*n-1)).

Terms

    a(0) =1a(1) =3a(2) =15a(3) =315a(4) =2835a(5) =155925a(6) =6081075a(7) =638512875a(8) =10854718875

External references