a(n) = Product_{k=1..n} (2*k*(k-1)+1).

A277347

a(n) = Product_{k=1..n} (2*k*(k-1)+1).

Terms

    a(0) =1a(1) =5a(2) =65a(3) =1625a(4) =66625a(5) =4064125a(6) =345450625a(7) =39035920625

External references