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 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 6 |
| 4 | 48 |
| 5 | 600 |
| 6 | 8640 |
| 7 | 151200 |
| 8 | 3064320 |
| 9 | 71124480 |
| 10 | 1857945600 |
| 11 | 54007430400 |
| 12 | 1729195776000 |
| 13 | 60483053030400 |
| 14 | 2294881337548800 |
| 15 | 93889711948032000 |
| 16 | 4120492394962944000 |
| 17 | 193100926276177920000 |
| 18 | 9624765220305371136000 |