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 | 5355 |
| 3 | 31040 |
| 4 | 94500 |
| 5 | 78624 |
| 6 | 201600 |
| 7 | 86400 |
| 8 | 226800 |
| 9 | 403200 |
| 10 | 90720 |
| 11 | 0 |
| 12 | 302400 |
| 13 | 0 |
| 14 | 0 |
| 15 | 120960 |
| 16 | 0 |
| 17 | 0 |
| 18 | 0 |
| 19 | 0 |
| 20 | 0 |
| 21 | 172800 |