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 | 38 |
| 4 | 1834 |
| 5 | 419710 |
| 6 | 356269056 |
| 7 | 1163645044100 |
| 8 | 15000387107144576 |
| 9 | 749707067231291403016 |