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 | 15 |
| 3 | 7 |
| 4 | 21 |
| 5 | 108 |
| 6 | 2268 |
| 7 | 5040 |
| 8 | 79380 |
| 9 | 20575296 |
| 10 | 147 |
| 11 | 1134 |
| 12 | 102060 |
| 13 | 555660 |
| 14 | 1102248 |
| 15 | 1524096 |
| 16 | 48988800 |
| 17 | 1365590016 |
| 18 | 17360406 |
| 19 | 437482231200 |
| 20 | 559977255936 |
| 21 | 92876046336 |
| 22 | 743317957509120 |
| 23 | 4592700000000 |
| 24 | 133978933305000000 |