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) |
|---|---|
| 0 | 1 |
| 1 | 4 |
| 2 | 24 |
| 3 | 416 |
| 4 | 34400 |
| 5 | 13561728 |
| 6 | 22961051392 |
| 7 | 160934805885952 |
| 8 | 4612329945733989888 |
| 9 | 537318814887463743641600 |
| 10 | 253532269357851227988228362240 |
| 11 | 483356648964255814869226601582346240 |