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 | 48 |
| 2 | 495452160 |
| 3 | 38903149816763645952000 |
| 4 | 127654439655255918929515331054014121902080000 |