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 | 3 |
| 3 | 15 |
| 4 | 176 |
| 5 | 6842 |
| 6 | 1505499 |
| 7 | 3913864295 |
| 8 | 338854264248680 |
| 9 | 4216199393504640098482 |
| 10 | 59475094770587936660132803278445 |
| 11 | 17618334934720173062514849536736413843694654543 |