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 | 2 |
| 2 | 3 |
| 3 | 30 |
| 4 | 72 |
| 5 | 1440 |
| 6 | 4536 |
| 7 | 142560 |
| 8 | 544320 |
| 9 | 23950080 |
| 10 | 106142400 |
| 11 | 6107270400 |
| 12 | 30569011200 |
| 13 | 2198617344000 |
| 14 | 12197035468800 |
| 15 | 1061932177152000 |
| 16 | 6440034727526400 |
| 17 | 662645678542848000 |
| 18 | 4347023441080320000 |