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A084965 Number of labeled totally ordered semigroups with n elements. 0
1, 1, 6, 44, 386, 3852, 42640, 516791, 6817378, 98091071, 1569786228 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Table of n, a(n) for n=0..10.

Petr Gajdoš and Martin Kuřil, Ordered semigroups of size at most 7 and linearly ordered semigroups of size at most 10, Semigroup Forum, 89 (2014), 639-663.

J. Slaney, FINDER: Finite Domain Enumerator

CROSSREFS

Cf. A023814.

Sequence in context: A147688 A090442 A286867 * A203159 A279085 A124996

Adjacent sequences:  A084962 A084963 A084964 * A084966 A084967 A084968

KEYWORD

nonn,hard,more

AUTHOR

Michael Somos, Jun 15 2003

EXTENSIONS

a(9)-a(10) from Gajdoš and Kuřil added by Andrey Zabolotskiy, Mar 24 2021

STATUS

approved

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Last modified October 24 13:43 EDT 2021. Contains 348232 sequences. (Running on oeis4.)