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) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 96 |
| 7 | 1904 |
| 8 | 23040 |
| 9 | 221184 |
| 10 | 1858560 |
| 11 | 14353152 |
| 12 | 104742912 |
| 13 | 734769152 |
| 14 | 5010432000 |
| 15 | 33464217600 |
| 16 | 220066480128 |
| 17 | 1430279159808 |
| 18 | 9212045819904 |
| 19 | 58914039332864 |
| 20 | 374665295953920 |
| 21 | 2371935399837696 |
| 22 | 14960708435312640 |
| 23 | 94072038170296320 |
| 24 | 589975504803594240 |