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 | 1 |
| 2 | 4 |
| 3 | 112 |
| 4 | 144 |
| 5 | 23400 |
| 6 | 28224 |
| 7 | 247104 |
| 8 | 604800 |
| 9 | 26812800 |
| 10 | 2677752000 |
| 11 | 6805814400 |
| 12 | 165145780800 |
| 13 | 1248124550400 |
| 14 | 17996854730400 |
| 15 | 388778796252000 |