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 | 0 |
| 2 | 39600 |
| 3 | 87859200 |
| 4 | 20779902000 |
| 5 | 1441891123200 |
| 6 | 46065617928000 |
| 7 | 861717856665600 |
| 8 | 10894640750334000 |
| 9 | 102119813013504000 |
| 10 | 755967560945968800 |
| 11 | 4623420024622080000 |
| 12 | 24151651608982497600 |
| 13 | 110516220812493619200 |