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 | 1 |
| 3 | 2 |
| 4 | 330 |
| 5 | 10830 |
| 6 | 25410 |
| 7 | 512820 |
| 8 | 512820 |
| 9 | 12960606120 |
| 10 | 434491727670 |
| 11 | 1893245380950 |
| 12 | 71023095613470 |
| 13 | 878232256181280 |
| 14 | 11429352906540438870 |