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 | 2 |
| 3 | 3 |
| 4 | 15 |
| 5 | 18432 |
| 6 | 75600 |
| 7 | 276531978240000 |
| 8 | 4810168001497883738112000 |
| 9 | 215788176336727572480000000 |
| 10 | 2178419737991700039289327133392896000000000000 |