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 | 1 |
| 1 | 4 |
| 2 | 32 |
| 3 | 336 |
| 4 | 4032 |
| 5 | 52352 |
| 6 | 716032 |
| 7 | 10161408 |
| 8 | 148229120 |
| 9 | 2208921600 |
| 10 | 33482670080 |
| 11 | 514630230016 |
| 12 | 8001860567040 |
| 13 | 125640146354176 |
| 14 | 1989285578473472 |
| 15 | 31725578742464512 |
| 16 | 509178657425326080 |
| 17 | 8217766225008656384 |
| 18 | 133287551280741351424 |
| 19 | 2171450128344786403328 |