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 | 0 |
| 1 | 1 |
| 2 | 4 |
| 3 | 17 |
| 4 | 83 |
| 5 | 461 |
| 6 | 2873 |
| 7 | 19846 |
| 8 | 150418 |
| 9 | 1240398 |
| 10 | 11051017 |
| 11 | 105740309 |
| 12 | 1081101474 |
| 13 | 11758967146 |
| 14 | 135544030566 |
| 15 | 1650178088102 |
| 16 | 21155166649234 |
| 17 | 284821038726404 |
| 18 | 4017445572746953 |
| 19 | 59238368957321225 |
| 20 | 911319667593472401 |
| 21 | 14600491369553323529 |
| 22 | 243205500769215401307 |