A351731 Number of labeled idempotent monoids of order n.

1, 2, 12, 140, 3020, 100362, 4768624, 305498328, 25293331098, 2619996058190

Offset

1,2

Links

Table of n, a(n) for n=1..10.

Formula

a(n) = n * A351731(n-1).

Crossrefs

Main diagonal of A058157.

Cf. A058153, A351730.

Sequence in context: A287885 A091144 A275829 * A240387 A087800 A009747

Adjacent sequences: A351728 A351729 A351730 * A351732 A351733 A351734

Keyword

nonn,hard,more

Author

Andrew Howroyd, Feb 17 2022

Status

approved