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 | 6 |
| 3 | 60 |
| 4 | 140 |
| 5 | 2520 |
| 6 | 27720 |
| 7 | 360360 |
| 8 | 360360 |
| 9 | 12252240 |
| 10 | 77597520 |
| 11 | 5173168 |
| 12 | 118982864 |
| 13 | 8923714800 |
| 14 | 80313433200 |
| 15 | 2329089562800 |
| 16 | 72201776446800 |
| 17 | 13127595717600 |
| 18 | 13127595717600 |
| 19 | 485721041551200 |
| 20 | 485721041551200 |
| 21 | 19914562703599200 |
| 22 | 122332313750680800 |