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 | 2 |
| 2 | 199 |
| 3 | 409 |
| 4 | 17569 |
| 5 | 981091 |
| 6 | 3918251 |
| 7 | 1329433951 |
| 8 | 75902670689 |
| 9 | 45048280453021 |