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 | 2 |
| 2 | 128 |
| 3 | 2802 |
| 4 | 183220 |
| 5 | 8870150 |
| 6 | 578826040 |
| 7 | 37121438930 |
| 8 | 2639009446600 |