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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 0 |
| 9 | 0 |
| 10 | 3265920 |
| 11 | 182891520 |
| 12 | 5751285120 |
| 13 | 134183589120 |
| 14 | 2592611400960 |
| 15 | 43947813288960 |
| 16 | 676736110229760 |
| 17 | 9685234777397760 |
| 18 | 130890592784891520 |
| 19 | 1689704521363998720 |
| 20 | 21016063609130056320 |
| 21 | 253507542701850904320 |
| 22 | 2981020379966298432000 |