OFFSET
1,2
LINKS
Andreas Distler, Classification and Enumeration of Finite Semigroups, A Thesis Submitted for the Degree of PhD, University of St Andrews (2010).
A. Distler and T. Kelsey, The semigroups of order 9 and their automorphism groups, arXiv preprint arXiv:1301.6023 [math.CO], 2013.
EXAMPLE
Triangle begins:
1;
2, 3;
5, 9, 10;
20, 50, 72, 46;
171, 309, 590, 594, 251;
...
CROSSREFS
KEYWORD
AUTHOR
Christian G. Bower, Nov 09 2000
EXTENSIONS
Updated Feb 19 2001
More terms from Andreas Distler, Jan 13 2011
STATUS
approved