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) |
|---|---|
| 2 | 4 |
| 3 | 90 |
| 4 | 12424 |
| 5 | 2808172 |
| 6 | 449235282 |
| 7 | 107282960684 |
| 8 | 5345302912844 |
| 9 | 102834566977650 |