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 | 0 |
| 1 | 40320 |
| 2 | 362880 |
| 3 | 1814400 |
| 4 | 6652800 |
| 5 | 19958400 |
| 6 | 51891840 |
| 7 | 121080960 |
| 8 | 259459200 |
| 9 | 518918400 |
| 10 | 980179200 |
| 11 | 1764322560 |
| 12 | 3047466240 |
| 13 | 5079110400 |
| 14 | 8204716800 |
| 15 | 12893126400 |
| 16 | 19769460480 |
| 17 | 29654190720 |
| 18 | 43609104000 |
| 19 | 62990928000 |
| 20 | 89513424000 |
| 21 | 125318793600 |
| 22 | 173059286400 |