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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 5040 |
| 9 | 45360 |
| 10 | 226800 |
| 11 | 831600 |
| 12 | 9979200 |
| 13 | 103783680 |
| 14 | 2058376320 |
| 15 | 23870246400 |
| 16 | 265686220800 |
| 17 | 2477893017600 |
| 18 | 47031546481920 |
| 19 | 656384611034880 |
| 20 | 11972743148620800 |
| 21 | 165640695384729600 |
| 22 | 1969108505560627200 |