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 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 25 |
| 5 | 106 |
| 6 | 708 |
| 7 | 22711 |
| 8 | 670449 |
| 9 | 44864449 |
| 10 | 5122273171 |
| 11 | 1106078073333 |
| 12 | 426788297174150 |