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 | 1 |
| 2 | 8 |
| 3 | 220 |
| 4 | 21111 |
| 5 | 6896530 |
| 6 | 7790212998 |
| 7 | 30260326859957 |
| 8 | 404132235613627376 |
| 9 | 18556239226034408691425 |