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 | 3 |
| 2 | 727 |
| 3 | 20922789928321 |
| 4 | 403291461126605641811020801 |
| 5 | 523022617466601111760007224221719391608832001 |