Complementary sequences (e.g.: 111010 and 000101) are taken to be equivalent. Related to maximum order complexity of sequences and also to number of incomplete paths in a De Bruijn graph

REFERENCES

C. J. A. Jansen, Investigations On Nonlinear Stream cipher Systems: Construction and Evaluation Methods, Ph.D. Thesis, Delft University of Technology, The Netherlands (1989), pp. 58-81