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 | 16 |
| 5 | 280 |
| 6 | 56448 |
| 7 | 118594560 |
| 8 | 4282251214848 |
| 9 | 3398378138678329344 |
| 10 | 75807214831601328114892800 |