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) |
|---|---|
| 7 | 1 |
| 8 | 2 |
| 9 | 18 |
| 10 | 3564 |
| 11 | 393454160 |
| 12 | 24410990062379593896 |