Let zeta be a primitive 2(m)th root of unity. We prove that Z[alpha] = Z[ze
ta] if and only if alpha = n +/- zeta ' for some n, i is an element of Z, i
odd. This is the first example of number fields of;arbitrarily large degre
e for which all power bases for the ring of integers are known. (C) 2001 Ac
ademic Press.