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 | 5 |
| 2 | 135 |
| 3 | 21331 |
| 4 | 35452250 |
| 5 | 843211336888 |
| 6 | 322942973130396495 |
| 7 | 2131384087795458774515411 |