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 | 2 |
| 4 | 8 |
| 5 | 12 |
| 6 | 22 |
| 7 | 58 |
| 8 | 276 |
| 9 | 648 |
| 10 | 2304 |
| 11 | 6508 |
| 12 | 24528 |
| 13 | 96402 |
| 14 | 466922 |
| 15 | 2271738 |
| 16 | 13723826 |
| 17 | 76579326 |
| 18 | 512425626 |
| 19 | 3281233020 |
| 20 | 24654941268 |
| 21 | 175398054696 |