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) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 24 |
| 5 | 480 |
| 6 | 10080 |
| 7 | 262080 |
| 8 | 8104320 |
| 9 | 287400960 |
| 10 | 11496038400 |
| 11 | 512691379200 |
| 12 | 25231888281600 |
| 13 | 1358412133478400 |
| 14 | 79419074570035200 |
| 15 | 5011102330730496000 |
| 16 | 339416862385176576000 |
| 17 | 24564200609223475200000 |