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 | 0 |
| 2 | 20 |
| 3 | 264 |
| 4 | 2550 |
| 5 | 22267 |
| 6 | 166762 |
| 7 | 1046418 |
| 8 | 5586207 |
| 9 | 25997719 |
| 10 | 107862842 |
| 11 | 406276442 |
| 12 | 1409360487 |
| 13 | 4554092377 |
| 14 | 13832291491 |
| 15 | 39781304005 |
| 16 | 108983918717 |
| 17 | 285829839116 |
| 18 | 720662237189 |
| 19 | 1752986235171 |
| 20 | 4126404034476 |
| 21 | 9424479791691 |
| 22 | 20933182989114 |