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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 24 |
| 6 | 864 |
| 7 | 24192 |
| 8 | 653184 |
| 9 | 18144000 |
| 10 | 531365184 |
| 11 | 16563076992 |
| 12 | 551172885120 |
| 13 | 19580825392128 |
| 14 | 741547690884000 |
| 15 | 29873618711000064 |
| 16 | 1277121733631347968 |
| 17 | 57795924098354577408 |
| 18 | 2762004604309125452928 |
| 19 | 139058300756829929472000 |
| 20 | 7359536118308288021017344 |