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) |
|---|---|
| 2 | 0 |
| 3 | 1 |
| 4 | 8 |
| 5 | 75 |
| 6 | 864 |
| 7 | 12005 |
| 8 | 196608 |
| 9 | 3720087 |
| 10 | 80000000 |
| 11 | 1929229929 |
| 12 | 51597803520 |
| 13 | 1516443410339 |
| 14 | 48594782035968 |
| 15 | 1686702392578125 |
| 16 | 63050394783186944 |
| 17 | 2525667398391013935 |
| 18 | 107946249863639334912 |
| 19 | 4903504030649559850577 |
| 20 | 235929600000000000000000 |