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 | 1 |
| 2 | 3 |
| 3 | 135 |
| 4 | 212625 |
| 5 | 21097715625 |
| 6 | 207248662456171875 |
| 7 | 291128066470548703880859375 |
| 8 | 79746389028864195813528714933837890625 |
| 9 | 5570294521107277357810167397301815834831695556640625 |