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A234843 Number of commutative inverse semigroups of order n. 3
1, 2, 5, 16, 51, 201, 877, 4443, 25284, 161698, 1145508, 8910291, 75373563, 687950735, 6727985390 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..15.

Martin E. Malandro, Enumeration of finite inverse semigroups, arXiv:1312.7192 [math.CO]

CROSSREFS

Cf. A001428 (inverse semigroups), A234844 (inverse monoids), A234845 (commutative inverse monoids).

Sequence in context: A268213 A231357 A303477 * A011819 A148390 A232317

Adjacent sequences:  A234840 A234841 A234842 * A234844 A234845 A234846

KEYWORD

nonn,hard,more

AUTHOR

Joerg Arndt, Dec 31 2013

STATUS

approved

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Last modified September 23 16:41 EDT 2020. Contains 337315 sequences. (Running on oeis4.)