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 | 16 |
| 3 | 320 |
| 4 | 2256 |
| 5 | 3712 |
| 6 | 34960 |
| 7 | 41520 |
| 8 | 183696 |
| 9 | 3496800 |
| 10 | 31596672 |
| 11 | 31531872 |
| 12 | 278474880 |
| 13 | 326952560 |
| 14 | 2066242576 |
| 15 | 2516902752 |
| 16 | 2598744000 |
| 17 | 26531651360 |
| 18 | 23087388720 |
| 19 | 167365651216 |
| 20 | 203869268832 |
| 21 | 211282856832 |
| 22 | 2184410558000 |