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) |
|---|---|
| 2 | 12 |
| 3 | 105 |
| 4 | 831 |
| 5 | 6648 |
| 6 | 53545 |
| 7 | 434458 |
| 8 | 3548871 |
| 9 | 29166324 |
| 10 | 241006333 |
| 11 | 2001145585 |
| 12 | 16688238416 |
| 13 | 139711675493 |
| 14 | 1173762075101 |
| 15 | 9892582661593 |
| 16 | 83617537623039 |
| 17 | 708654873428000 |
| 18 | 6020421349942965 |
| 19 | 51261344063828713 |
| 20 | 437370998284452284 |
| 21 | 3738875265960650016 |