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 | 2 |
| 2 | 8 |
| 3 | 46 |
| 4 | 320 |
| 5 | 2500 |
| 6 | 21120 |
| 7 | 188758 |
| 8 | 1760256 |
| 9 | 16969756 |
| 10 | 168022016 |
| 11 | 1700483916 |
| 12 | 17527963648 |
| 13 | 183499999368 |
| 14 | 1946861076480 |
| 15 | 20896083575142 |
| 16 | 226570927865856 |
| 17 | 2478789884919084 |
| 18 | 27336509563600896 |
| 19 | 303635676268456996 |
| 20 | 3394385993908879360 |
| 21 | 38168423356190965688 |
| 22 | 431472747874361540608 |