Pick any length n binary string b1b2⋯bn and remove the first bit b1. If b2b3⋯bn1 is a necklace, then append the complement of b1 to the end of the remaining string; otherwise append b1. By repeating this process, eventually all 2n binary strings will be visited cyclically. This shift rule leads to a new de Bruijn sequence construction that can be generated in O(1)-amortized time per bit.