%I #7 Mar 24 2021 13:54:20
%S 1,1,6,44,386,3852,42640,516791,6817378,98091071,1569786228
%N Number of labeled totally ordered semigroups with n elements.
%H Petr Gajdoš and Martin Kuřil, <a href="https://doi.org/10.1007/s00233-014-9602-3">Ordered semigroups of size at most 7 and linearly ordered semigroups of size at most 10</a>, Semigroup Forum, 89 (2014), 639-663.
%H J. Slaney, <a href="ftp://arp.anu.edu.au/pub/papers/slaney/finder/finder.ps.gz">FINDER: Finite Domain Enumerator</a>
%Y Cf. A023814.
%K nonn,hard,more
%O 0,3
%A _Michael Somos_, Jun 15 2003
%E a(9)-a(10) from Gajdoš and Kuřil added by _Andrey Zabolotskiy_, Mar 24 2021