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

A277352

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

Terms

    a(0) =1a(1) =3a(2) =27a(3) =513a(4) =16929a(5) =863379a(6) =63026667a(7) =6239640033a(8) =804913564257

External references