A038022 Triangle: T(n,k), k<=n: commutative groupoids with no symmetry with n elements and k idempotents.

1, 0, 1, 1, 2, 1, 35, 51, 27, 3, 13776, 18330, 9152, 2016, 164, 83306272, 104124850, 52056277, 13006746, 1622527, 80461

Offset

0,5

Links

Table of n, a(n) for n=0..20.

Index entries for sequences related to groupoids

Crossrefs

Cf. A001329, A001425, A030258, A030261, A030264.

Sequence in context: A113456 A205445 A127608 * A173838 A038021 A127609

Adjacent sequences: A038019 A038020 A038021 * A038023 A038024 A038025

Keyword

nonn,tabl,more

Author

Christian G. Bower, May 15 1998

Status

approved