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 | 22 |
| 4 | 384 |
| 5 | 19080 |
| 6 | 1019328 |
| 7 | 106546608 |
| 8 | 11075595648 |
| 9 | 1892644922880 |
| 10 | 321721729436160 |
| 11 | 81376293539485440 |
| 12 | 20506177206967265280 |