Issue No. 08 - August (1984 vol. 33)
M. C. Er , Department of Computing Science, University of Wollongong, Wollongong, Australia.
The definition of the N-ary reflected Gray code is given. Two recursive algorithms for generating the N-ary reflected Gray codes are presented: one algorithm is coded directly from the definition; another algorithm is derived from the sequencing orders of digits in the N-ary reflected Gray codes. It is shown that these two algorithms are equivalent functionally. Furthermore, it is proven that the N-ary reflected Gray code is cyclic when its radix is even, but not cyclic, in general, when its radix is odd.
M. C. Er, "On Generating the N-ary Reflected Gray Codes", IEEE Transactions on Computers, vol. 33, no. , pp. 739-741, August 1984, doi:10.1109/TC.1984.5009360