A030254 Number of nonisomorphic groupoids with 1 idempotent and a nontrivial symmetry.

0, 0, 54, 12664

Offset

1,3

Links

Table of n, a(n) for n=1..4.

Index entries for sequences related to groupoids

Formula

a(n) = A030253(n) - A030271(n).

Crossrefs

Column k=1 of A038020.

Cf. A030253, A030271.

Sequence in context: A299949 A228607 A364304 * A085482 A084226 A071800

Adjacent sequences: A030251 A030252 A030253 * A030255 A030256 A030257

Keyword

nonn,more

Author

Christian G. Bower

Extensions

a(3) corrected by Andrew Howroyd, Feb 02 2023

Status

approved