
REFERENCES

Grillet, P.A., Computing Finite Commutative Semigroups, Semigroup Forum 53 (1996), 140154.
Grillet, P.A., Computing Finite Commutative Semigroups: Part II, Semigroup Forum 67 (2003), 159184.
H. Juergensen and P. Wick, Die Halbgruppen von Ordnungen <= 7, Semigroup Forum, 14 (1977), 6979.
R. J. Plemmons, There are 15973 semigroups of order 6, Math. Algor., 2 (1967), 217; 3 (1968), 23.
R. J. Plemmons, Cayley Tables for All Semigroups of Order Less Than 7. Department of Mathematics, Auburn Univ., 1965.
Satoh, S.; Yama, K.; and Tokizawa, M., Semigroups of order 8, Semigroup Forum 49 (1994), 729.
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).
