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 | 0 |
| 1 | 6 |
| 2 | 144 |
| 3 | 1944 |
| 4 | 20736 |
| 5 | 194400 |
| 6 | 1679616 |
| 7 | 13716864 |
| 8 | 107495424 |
| 9 | 816293376 |
| 10 | 6046617600 |
| 11 | 43898443776 |
| 12 | 313456656384 |
| 13 | 2207257288704 |
| 14 | 15359376162816 |
| 15 | 105791621529600 |
| 16 | 722204136308736 |
| 17 | 4891804579528704 |
| 18 | 32905425960566784 |