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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 210 |
| 8 | 5040 |
| 9 | 37800 |
| 10 | 201600 |
| 11 | 2044350 |
| 12 | 25530120 |
| 13 | 213993780 |
| 14 | 1692490800 |
| 15 | 19767998250 |
| 16 | 232823791200 |
| 17 | 2235629476080 |
| 18 | 23171222430720 |
| 19 | 294649445112750 |
| 20 | 4300403589581400 |
| 21 | 55176842335916700 |
| 22 | 660577269463243440 |