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) |
|---|---|
| 8 | 1 |
| 9 | 2 |
| 10 | 20 |
| 11 | 7658 |
| 12 | 12954016496 |
| 13 | 10592917773063552232751878 |