a(n) = (3*n - 1)^(n-1).A274265a(n) = (3*n - 1)^(n-1).Terms a(0) =1a(1) =5a(2) =64a(3) =1331a(4) =38416a(5) =1419857a(6) =64000000a(7) =3404825447a(8) =208827064576External referencesoeis: A274265