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 | 31 |
| 3 | 45361 |
| 4 | 3991681 |
| 5 | 2516506653355019284889240277665777045474566836669417196965412366518489408149127168000000000000001 |