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 | 6 |
| 4 | 23 |
| 5 | 84 |
| 6 | 897 |
| 7 | 9292 |
| 8 | 98776 |
| 9 | 1380544 |
| 10 | 20573376 |
| 11 | 451512320 |
| 12 | 8653964800 |
| 13 | 238280574976 |
| 14 | 6409517629440 |
| 15 | 172949221113856 |