A058112 Number of isomorphism classes of idempotent semigroups of order n.

1, 1, 3, 10, 46, 251, 1682, 13213, 119826, 1228712

Offset

0,3

Links

Table of n, a(n) for n=0..9.

Index entries for sequences related to monoids

Index entries for sequences related to semigroups

Crossrefs

Main diagonal of A058108 and A058137.

Cf. A027851, A351730 (labeled).

Sequence in context: A371549 A074508 A143500 * A345132 A020008 A167999

Adjacent sequences: A058109 A058110 A058111 * A058113 A058114 A058115

Keyword

nonn,hard

Author

Christian G. Bower, Nov 09 2000

Extensions

Updated Feb 19 2001

a(8)-a(9) added by Andrew Howroyd, Feb 17 2022

Status

approved