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 | 1 |
| 3 | 2 |
| 4 | 6 |
| 5 | 25 |
| 6 | 116 |
| 7 | 625 |
| 8 | 3757 |
| 9 | 25140 |
| 10 | 184511 |
| 11 | 1473861 |
| 12 | 12711339 |
| 13 | 117598686 |
| 14 | 1160399052 |
| 15 | 12152333659 |
| 16 | 134487937252 |
| 17 | 1566878426731 |
| 18 | 19154490559458 |