Chris North
A Binary Gray Code of order n is a listing of all 2^n length n binary strings such that consecutive strings differ in exactly one bit position. Various restrictions can be placed on this definition, yielding Gray Codes with certain useful properties. In this talk, we introduce a new restriction proposed by Stevens. A Beckett Gray Code of order n is a listing of all 2^n length n binary strings such that consecutive strings differ in exactly one bit position and where only the bit that has been 1 the longest may change to 0. The motivation for this definition comes from the play "Quad" by Samuel Beckett. We will describe an efficient combinatorial search algorithm for finding Beckett Gray Codes, the parallelization of this algorithm and results produced by it.