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 | 1 |
| 2 | 8 |
| 3 | 168 |
| 4 | 6720 |
| 5 | 436800 |
| 6 | 41932800 |
| 7 | 5577062400 |
| 8 | 981562982400 |
| 9 | 220851671040000 |
| 10 | 61838467891200000 |
| 11 | 21086917550899200000 |
| 12 | 8603462360766873600000 |
| 13 | 4138265395528866201600000 |
| 14 | 2317428621496165072896000000 |
| 15 | 1494741460865026472017920000000 |
| 16 | 1100129715196659483405189120000000 |