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 | 84 |
| 3 | 1680 |
| 4 | 66276 |
| 5 | 2731680 |
| 6 | 128704800 |
| 7 | 6555265920 |
| 8 | 355588928100 |
| 9 | 20247799145280 |
| 10 | 1198746727590384 |
| 11 | 73266532153214400 |
| 12 | 4598338364703822816 |
| 13 | 295145004688715301120 |
| 14 | 19311431876483926443264 |