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 | 1 |
| 1 | 1 |
| 2 | 6 |
| 3 | 4 |
| 4 | 180 |
| 5 | 168 |
| 6 | 12960 |
| 7 | 15120 |
| 8 | 1710720 |
| 9 | 2358720 |
| 10 | 359251200 |
| 11 | 566092800 |
| 12 | 109930867200 |
| 13 | 193603737600 |
| 14 | 46170964224000 |
| 15 | 89444926771200 |
| 16 | 25486372251648000 |
| 17 | 53666956062720000 |