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 | 0 |
| 1 | 8 |
| 2 | 288 |
| 3 | 6672 |
| 4 | 65840 |
| 5 | 391320 |
| 6 | 1681008 |
| 7 | 5767328 |
| 8 | 16781472 |
| 9 | 43053480 |
| 10 | 100010240 |
| 11 | 214373808 |
| 12 | 430002768 |
| 13 | 815759672 |
| 14 | 1475827920 |
| 15 | 2562941760 |
| 16 | 4295033408 |
| 17 | 6975841608 |
| 18 | 11020066272 |
| 19 | 16983694160 |
| 20 | 25600160880 |
| 21 | 37823054808 |
| 22 | 54876108848 |