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 | 1 |
| 1 | 5 |
| 2 | 60 |
| 3 | 1260 |
| 4 | 40320 |
| 5 | 1814400 |
| 6 | 108864000 |
| 7 | 8382528000 |
| 8 | 804722688000 |
| 9 | 94152554496000 |
| 10 | 13181357629440000 |
| 11 | 2174924008857600000 |
| 12 | 417585409700659200000 |
| 13 | 92286375543845683200000 |
| 14 | 23256166637049112166400000 |
| 15 | 6628007491558996967424000000 |