A234843 Number of commutative inverse semigroups of order n.

1, 2, 5, 16, 51, 201, 877, 4443, 25284, 161698, 1145508, 8910291, 75373563, 687950735, 6727985390

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