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) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 6 |
| 4 | 24 |
| 5 | 96 |
| 6 | 336 |
| 7 | 672 |
| 8 | 3024 |
| 9 | 9072 |
| 10 | 35280 |
| 11 | 120960 |
| 12 | 483840 |
| 13 | 1874880 |
| 14 | 10108800 |
| 15 | 20217600 |
| 16 | 107827200 |
| 17 | 398131200 |
| 18 | 1919877120 |
| 19 | 6051594240 |
| 20 | 24710676480 |
| 21 | 86487367680 |
| 22 | 339771801600 |
| 23 | 1141066967040 |
| 24 | 4122564526080 |
| 25 | 16784726999040 |