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 | 3 |
| 2 | 18 |
| 3 | 2268 |
| 4 | 13608 |
| 5 | 1857492 |
| 6 | 133739424 |
| 7 | 53362030176 |
| 8 | 640344362112 |
| 9 | 561902177753280 |
| 10 | 23599891465637760 |
| 11 | 17558319250434493440 |
| 12 | 442469645110949234688 |
| 13 | 6065595130003447583720448 |
| 14 | 2547549954601447985162588160 |
| 15 | 985901832430760370257921617920 |
| 16 | 23661643978338248886190118830080 |