A027851 Number of nonisomorphic semigroups of order n.
1, 1, 5, 24, 188, 1915, 28634, 1627672, 3684030417, 105978177936292
Offset: 0
Links
- Özgur Akgun, Mun See Chang, Ian P. Gent, and Christopher Jefferson, Breaking the Symmetries of Indistinguishable Objects, arXiv:2503.17251 [cs.AI], 2025. See pp. 14, 17.
- Peter Cameron's Blog, The combinatorial explosion, Posted 18/02/2016.
- 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.
- C. Noebauer, Home page
- C. Noebauer, The Numbers of Small Rings
- C. Noebauer, Thesis on the enumeration of near-rings
- Eric Postpischil Posting to sci.math newsgroup, May 21 1990
- Arman Shamsgovara, Enumerating, Cataloguing and Classifying All Quantales on up to Nine Elements, In: Glück, R., Santocanale, L., and Winter, M. (eds), Relational and Algebraic Methods in Computer Science (RAMiCS 2023) Lecture Notes in Computer Science, Springer, Cham, Vol. 13896.
- Jeremy G. Sumner, Michael D. Woodhams, Lie-Markov models derived from finite semigroups, arXiv:1709.00520 [math.GR], 2017.
- Michael Torpey, Semigroup congruences: computational techniques and theoretical applications, Ph.D. Thesis, University of St. Andrews (Scotland, 2019).
- A. de Vries, Formal Languages: An Introduction, 2012.
- Eric Weisstein's World of Mathematics, Semigroup.
- Index entries for sequences related to semigroups
Extensions
a(8)-a(9) from Andreas Distler, Jan 13 2011