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 | 2664 |
| 4 | 551232 |
| 5 | 12319200 |
| 6 | 118332000 |
| 7 | 709921800 |
| 8 | 3141298944 |
| 9 | 11217854592 |
| 10 | 34149988800 |
| 11 | 91867386600 |
| 12 | 223898241600 |