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) |
|---|---|
| 1 | 0 |
| 2 | 2 |
| 3 | 58 |
| 4 | 2474 |
| 5 | 180480 |
| 6 | 19895936 |
| 7 | 3105348340 |
| 8 | 652948189204 |
| 9 | 177662757810868 |
| 10 | 60772232945639507 |
| 11 | 25533219938917963508 |
| 12 | 12921764841857675170314 |
| 13 | 7754002391777621430686566 |