a(n) = Product_{k=1..n} (4*k^2+1).

A277354

a(n) = Product_{k=1..n} (4*k^2+1).

Terms

    a(0) =1a(1) =5a(2) =85a(3) =3145a(4) =204425a(5) =20646925a(6) =2993804125a(7) =589779412625

External references