A030252 Number of nonisomorphic groupoids with no idempotents and a nontrivial symmetry.
0, 0, 2, 9, 15376
Offset: 0
This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.