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 | 12 |
| 2 | 288 |
| 3 | 10368 |
| 4 | 497664 |
| 5 | 29859840 |
| 6 | 2149908480 |
| 7 | 180592312320 |
| 8 | 17336861982720 |
| 9 | 1872381094133760 |
| 10 | 224685731296051200 |
| 11 | 29658516531078758400 |
| 12 | 4270826380475341209600 |
| 13 | 666248915354153228697600 |