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 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 3 |
| 6 | 1 |
| 7 | 20 |
| 8 | 15 |
| 9 | 35 |
| 10 | 7 |
| 11 | 36288 |
| 12 | 35 |
| 13 | 277200 |
| 14 | 1485 |
| 15 | 4576 |
| 16 | 9009 |
| 17 | 20432412000 |
| 18 | 5005 |
| 19 | 1097800704000 |
| 20 | 459459 |
| 21 | 5912192 |
| 22 | 2834325 |
| 23 | 2322315553259520000 |
| 24 | 1616615 |
| 25 | 124672148625024 |
| 26 | 4865140665 |