
REFERENCES

M. A. Harrison, On the number of classes of switching networks, J. Franklin Instit., 276 (1963), 313327.
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
