a(n) = Product_{k=0..n} (2^(2k+1)+1).A085521a(n) = Product_{k=0..n} (2^(2k+1)+1).Terms a(0) =1a(1) =3a(2) =27a(3) =891a(4) =114939a(5) =58963707a(6) =120816635643External referencesoeis: A085521