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 | 0 |
| 8 | 0 |
| 9 | 362880 |
| 10 | 3265920 |
| 11 | 33022080 |
| 12 | 369774720 |
| 13 | 4536362880 |
| 14 | 60451816320 |
| 15 | 869007242880 |
| 16 | 13397819541120 |
| 17 | 220448163358080 |
| 18 | 3854801333416320 |
| 19 | 71370457471716480 |
| 20 | 1394586705296776320 |
| 21 | 28676809138124407680 |
| 22 | 618948032364173877120 |