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 | 5 |
| 1 | 120 |
| 2 | 1840 |
| 3 | 27552 |
| 4 | 421248 |
| 5 | 6613504 |
| 6 | 106441472 |
| 7 | 1750927872 |