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 | 3 |
| 4 | 24 |
| 5 | 5 |
| 6 | 1800 |
| 7 | 7 |
| 8 | 15680 |
| 9 | 756 |
| 10 | 113400 |
| 11 | 11 |
| 12 | 79693891200 |
| 13 | 13 |
| 14 | 4372368 |
| 15 | 20495475 |
| 16 | 44972928000 |
| 17 | 17 |
| 18 | 2028339316523520 |
| 19 | 19 |
| 20 | 52737518268864000 |
| 21 | 3247700400 |
| 22 | 3585005424 |
| 23 | 23 |
| 24 | 38135556819759802035135799296 |
| 25 | 1328250 |
| 26 | 87885070000 |
| 27 | 370142004375 |
| 28 | 10293527616645873600000 |
| 29 | 29 |