

A058129


Number of monoids (semigroups with identity) of order n.


12




OFFSET

0,3


LINKS

Table of n, a(n) for n=0..8.
Eric Postpischil, Posting to sci.math newsgroup, May 21 1990
Index entries for sequences related to monoids


FORMULA

a(n) = 2*A058133(n)  A058132(n).
a(n) < A027851(n) except for equality iff n = 1.  M. F. Hasler, Dec 10 2018


CROSSREFS

Cf. A058132, A058133.
Cf. A027851 (number of all nonisomorphic semigroups).
Sequence in context: A014307 A000154 A003713 * A101514 A247240 A266356
Adjacent sequences: A058126 A058127 A058128 * A058130 A058131 A058132


KEYWORD

nonn,hard,more


AUTHOR

Christian G. Bower, Nov 13 2000


EXTENSIONS

a(8) from Christian G. Bower, Dec 26 2006
a(0) = 0 prepended by M. F. Hasler, Dec 10 2018


STATUS

approved



