A058117 Number of commutative semigroups of order n with 1 idempotent.

1, 2, 5, 16, 62, 342, 3435

Offset

1,2

Links

Table of n, a(n) for n=1..7.

Index entries for sequences related to semigroups

Crossrefs

Column 1 of A058116.

Sequence in context: A144188 A157314 A159603 * A007124 A112951 A124470

Adjacent sequences: A058114 A058115 A058116 * A058118 A058119 A058120

Keyword

nonn,hard

Author

Christian G. Bower, Nov 09 2000

Status

approved