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 | 0 |
| 2 | 2 |
| 3 | 8 |
| 4 | 320 |
| 5 | 27584 |
| 6 | 6991360 |
| 7 | 5179178368 |
| 8 | 11396324458496 |
| 9 | 74944172892993536 |
| 10 | 1476405354971707604992 |
| 11 | 87208352627656970712229888 |
| 12 | 15450530398306943408625302896640 |
| 13 | 8211400756816955708062672318337859584 |