12710266442
domain: N
Appears in sequences
- Number of semigroups of order n with 2 idempotents, considered to be equivalent when they are isomorphic or anti-isomorphic (by reversal of the operator).at n=7A002787
- Triangle read by rows: semigroups of order n with k idempotents, considered to be equivalent when they are isomorphic or anti-isomorphic (by reversal of the operator).at n=37A058123