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) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 14 |
| 3 | 108 |
| 4 | 1180 |
| 5 | 15400 |
| 6 | 255400 |
| 7 | 4888960 |
| 8 | 109951360 |
| 9 | 2793984000 |
| 10 | 79855107200 |
| 11 | 2522981120000 |
| 12 | 87503244928000 |
| 13 | 3299660415744000 |
| 14 | 134477619593856000 |
| 15 | 5887149103503360000 |
| 16 | 275541626811601920000 |
| 17 | 13727736328568199168000 |
| 18 | 725335510624740370432000 |