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 | 2 |
| 3 | 5 |
| 4 | 16 |
| 5 | 57 |
| 6 | 231 |
| 7 | 1023 |
| 8 | 4926 |
| 9 | 25483 |
| 10 | 140601 |
| 11 | 822422 |
| 12 | 5074015 |
| 13 | 32881868 |
| 14 | 223027542 |
| 15 | 1578435549 |
| 16 | 11625317128 |
| 17 | 88894615929 |
| 18 | 704269188135 |
| 19 | 5770209550496 |
| 20 | 48810504348082 |
| 21 | 425650324975153 |
| 22 | 3821377057170313 |