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) |
|---|---|
| 2 | 1 |
| 3 | 10 |
| 4 | 42 |
| 5 | 352 |
| 6 | 1360 |
| 7 | 11616 |
| 8 | 43680 |
| 9 | 381952 |
| 10 | 1416960 |
| 11 | 12620800 |
| 12 | 46441472 |
| 13 | 419512320 |
| 14 | 1535352832 |
| 15 | 14021353472 |
| 16 | 51117465600 |
| 17 | 470886645760 |
| 18 | 1711716106240 |
| 19 | 15879295991808 |
| 20 | 57592095965184 |
| 21 | 537381547540480 |
| 22 | 1945481074704384 |