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 | 72 |
| 4 | 1536 |
| 5 | 14400 |
| 6 | 92160 |
| 7 | 470400 |
| 8 | 2064384 |
| 9 | 8128512 |
| 10 | 29491200 |
| 11 | 100362240 |
| 12 | 324403200 |
| 13 | 1005109248 |
| 14 | 3005743104 |
| 15 | 8722022400 |
| 16 | 24662507520 |
| 17 | 68183654400 |
| 18 | 184817811456 |
| 19 | 492285984768 |
| 20 | 1291006771200 |
| 21 | 3338686955520 |
| 22 | 8526181171200 |
| 23 | 21526669688832 |
| 24 | 53788022931456 |