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 | 1 |
| 4 | 2 |
| 5 | 1 |
| 6 | 1 |
| 7 | 6 |
| 8 | 24 |
| 9 | 2 |
| 10 | 1 |
| 11 | 24 |
| 12 | 20736 |
| 13 | 373248 |
| 14 | 16 |
| 15 | 1 |
| 16 | 120 |
| 17 | 995328000 |
| 18 | 189321481108517289984 |
| 19 | 12635683568857645056 |
| 20 | 2048 |
| 21 | 1 |