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 | 2 |
| 3 | 6 |
| 4 | 24 |
| 5 | 120 |
| 6 | 672 |
| 7 | 4128 |
| 8 | 28992 |
| 9 | 231936 |
| 10 | 2088960 |
| 11 | 20017152 |
| 12 | 207208704 |
| 13 | 2326900992 |
| 14 | 28338241536 |
| 15 | 373152276480 |
| 16 | 5206300028928 |