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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 1080 |
| 9 | 12960 |
| 10 | 143424 |
| 11 | 1641600 |
| 12 | 19915200 |
| 13 | 257644800 |
| 14 | 3556224000 |
| 15 | 52289556480 |
| 16 | 817133184000 |
| 17 | 13536585216000 |
| 18 | 237105792000000 |
| 19 | 4380335511552000 |
| 20 | 85148431867699200 |
| 21 | 1737742314147840000 |
| 22 | 37156364106301440000 |
| 23 | 830772012055265280000 |