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) |
|---|---|
| 0 | 5 |
| 1 | 6 |
| 2 | 14 |
| 3 | 48 |
| 4 | 216 |
| 5 | 1200 |
| 6 | 7920 |
| 7 | 60480 |
| 8 | 524160 |
| 9 | 5080320 |
| 10 | 54432000 |
| 11 | 638668800 |
| 12 | 8143027200 |
| 13 | 112086374400 |
| 14 | 1656387532800 |
| 15 | 26153487360000 |
| 16 | 439378587648000 |
| 17 | 7825123418112000 |
| 18 | 147254595231744000 |
| 19 | 2919482409811968000 |
| 20 | 60822550204416000000 |
| 21 | 1328364496464445440000 |