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 | 120 |
| 4 | 2400 |
| 5 | 33960 |
| 6 | 441600 |
| 7 | 5436960 |
| 8 | 64509840 |
| 9 | 745845120 |
| 10 | 8461348080 |
| 11 | 94558053840 |
| 12 | 1044594244080 |
| 13 | 11426874632880 |