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 | 0 |
| 3 | 0 |
| 4 | 64 |
| 5 | 5120 |
| 6 | 450560 |
| 7 | 56197120 |
| 8 | 10877927424 |
| 9 | 3407830056960 |
| 10 | 1765179884830720 |
| 11 | 1528596578057584640 |
| 12 | 2225354662890778394624 |
| 13 | 5460264388115266042593280 |
| 14 | 22602991882128566753395998720 |
| 15 | 157891665026904821204431467970560 |