A038019 Triangle: T(n,k), k<=n: groupoids with no symmetry with n elements and k idempotents.
1, 0, 1, 1, 4, 1, 969, 1431, 729, 108, 56615456, 75491208, 37741600, 8386560, 697501
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.