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 | 5040 |
| 3 | 665280 |
| 4 | 29059430400 |
| 5 | 8892185702400 |
| 6 | 1561112121913344000 |
| 7 | 423456034182935917363200000 |
| 8 | 368406749739154248105984000000 |
| 9 | 516657398319307246483332566876160000000 |