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) |
|---|---|
| 2 | 2 |
| 3 | 6 |
| 4 | 24 |
| 5 | 60 |
| 6 | 360 |
| 7 | 840 |
| 8 | 10080 |
| 9 | 7560 |
| 10 | 0 |
| 11 | 27720 |
| 12 | 332640 |
| 13 | 720720 |
| 14 | 0 |
| 15 | 10810800 |
| 16 | 17297280 |
| 17 | 36756720 |
| 18 | 1102701600 |
| 19 | 698377680 |
| 20 | 27935107200 |
| 21 | 48886437600 |
| 22 | 0 |
| 23 | 16062686640 |
| 24 | 385504479360 |
| 25 | 1204701498000 |
| 26 | 0 |
| 27 | 20238985166400 |
| 28 | 4497552259200 |
| 29 | 6987268688400 |
| 30 | 0 |
| 31 | 216605329340400 |