Howie, John M. An introduction to semigroup theory. (English) Zbl 0355.20056 London Mathematical Society Monographs. 7. London - New York - San Francisco: Academic Press: a subsidiary of Harcourt Brace Jovanovich, Publishers. X, 272 p. £9.80 (1976). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page Cited in 19 ReviewsCited in 821 Documents MSC: 20Mxx Semigroups 20-02 Research exposition (monographs, survey articles) pertaining to group theory PDF BibTeX XML OpenURL Online Encyclopedia of Integer Sequences: Array read by antidiagonals of products in the semigroup S = {(0,0), (i,j): i >= j >= 1} (see Comments for precise definition).