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.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 6 |
| 3 | 6 |
| 4 | 630 |
| 5 | 1398 |
| 6 | 93672 |
| 7 | 609264 |
| 8 | 20702760 |
| 9 | 279681294 |
| 10 | 7420195854 |
| 11 | 149049265998 |
| 12 | 3763960753368 |
| 13 | 88917911372016 |