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 | 809 |
| 2 | 821 |
| 3 | 1061 |
| 4 | 4294968101 |
| 5 | 18446744073709552421 |