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 | 8 |
| 3 | 80 |
| 4 | 720 |
| 5 | 6560 |
| 6 | 58960 |
| 7 | 531440 |
| 8 | 4782240 |
| 9 | 43046640 |
| 10 | 387413920 |
| 11 | 3486784400 |
| 12 | 31380999840 |
| 13 | 282429536480 |
| 14 | 2541865296880 |
| 15 | 22876792448320 |
| 16 | 205891127311680 |
| 17 | 1853020188851840 |
| 18 | 16677181656560880 |
| 19 | 150094635296999120 |
| 20 | 1350851717285570880 |
| 21 | 12157665459056397280 |