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 | 1 |
| 3 | 24 |
| 4 | 954 |
| 5 | 59040 |
| 6 | 5295150 |
| 7 | 651354480 |
| 8 | 105393619800 |
| 9 | 21717404916480 |
| 10 | 5554438422838200 |
| 11 | 1726882980691176000 |
| 12 | 641506478978753110800 |
| 13 | 280659563041747649760000 |
| 14 | 142843312073975729801785200 |
| 15 | 83684308104396267184700784000 |
| 16 | 55915646244745131440225950320000 |