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 | 4 |
| 3 | 24 |
| 4 | 216 |
| 5 | 2952 |
| 6 | 61488 |
| 7 | 1957392 |
| 8 | 95392296 |
| 9 | 7125411888 |
| 10 | 816458567400 |
| 11 | 143601085430064 |
| 12 | 38787148664334000 |
| 13 | 16094818374887017440 |
| 14 | 10263152688155204724288 |
| 15 | 10059484565080507620249504 |