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 | 3 |
| 1 | 0 |
| 2 | 24 |
| 3 | 48 |
| 4 | 120 |
| 5 | 648 |
| 6 | 1608 |
| 7 | 4176 |
| 8 | 21093 |
| 9 | 38064 |
| 10 | 175608 |
| 11 | 494616 |
| 12 | 1365726 |
| 13 | 5077200 |
| 14 | 13549704 |
| 15 | 43359768 |
| 16 | 140590629 |
| 17 | 389348688 |
| 18 | 1296882504 |
| 19 | 3834279072 |
| 20 | 11499126642 |
| 21 | 36680416368 |
| 22 | 107193301920 |
| 23 | 333178056720 |