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 | 2 |
| 3 | 8 |
| 4 | 68 |
| 5 | 1262 |
| 6 | 51420 |
| 7 | 4577274 |
| 8 | 888837716 |
| 9 | 376116199534 |
| 10 | 346688563051200 |
| 11 | 695975307003529228 |