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 | 1 |
| 2 | 2 |
| 3 | 1 |
| 4 | 12 |
| 5 | 8 |
| 6 | 240 |
| 7 | 180 |
| 8 | 1120 |
| 9 | 8064 |
| 10 | 725760 |
| 11 | 604800 |
| 12 | 79833600 |
| 13 | 68428800 |
| 14 | 830269440 |
| 15 | 10897286400 |
| 16 | 2615348736000 |
| 17 | 2324754432000 |
| 18 | 711374856192000 |
| 19 | 640237370572800 |
| 20 | 11585247657984000 |
| 21 | 221172909834240000 |
| 22 | 102181884343418880000 |
| 23 | 93666727314800640000 |