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) |
|---|---|
| 2 | 2 |
| 3 | 6 |
| 4 | 5 |
| 5 | 2 |
| 6 | 22 |
| 7 | 356 |
| 8 | 108 |
| 9 | 24 |
| 10 | 672 |
| 11 | 25056 |
| 12 | 4680 |
| 13 | 720 |
| 14 | 38160 |
| 15 | 2531520 |
| 16 | 342720 |
| 17 | 40320 |
| 18 | 3467520 |
| 19 | 358444800 |
| 20 | 38102400 |
| 21 | 3628800 |
| 22 | 460857600 |
| 23 | 68388364800 |
| 24 | 5987520000 |
| 25 | 479001600 |
| 26 | 84304281600 |
| 27 | 16979648716800 |
| 28 | 1264085222400 |
| 29 | 87178291200 |
| 30 | 20312541849600 |