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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 1 |
| 7 | 2 |
| 8 | 24 |
| 9 | 3136 |
| 10 | 29249425 |
| 11 | 2544489349890656 |
| 12 | 10469303814509319059584520878072 |
| 13 | 52390584919058211443518140875804297526718993867687450278537778 |