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 | 1584 |
| 5 | 75120 |
| 6 | 5601960 |
| 7 | 592956000 |
| 8 | 84557864160 |
| 9 | 15620794842240 |
| 10 | 3628800457682400 |
| 11 | 1035338990353113600 |
| 12 | 355902198996315787200 |
| 13 | 145077660657865961625600 |
| 14 | 69194697633957032681544000 |
| 15 | 38174841090323471644830720000 |
| 16 | 24122334398251368151021076928000 |