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 | 24 |
| 3 | 192 |
| 4 | 1248 |
| 5 | 7680 |
| 6 | 46464 |
| 7 | 279552 |
| 8 | 1678848 |
| 9 | 10076160 |
| 10 | 60463104 |
| 11 | 362790912 |
| 12 | 2176770048 |
| 13 | 13060669440 |
| 14 | 78364114944 |
| 15 | 470184886272 |
| 16 | 2821109710848 |
| 17 | 16926659051520 |
| 18 | 101559955881984 |
| 19 | 609359738437632 |
| 20 | 3656158436917248 |
| 21 | 21936950634086400 |
| 22 | 131621703829684224 |