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 | 64 |
| 5 | 600 |
| 6 | 6912 |
| 7 | 29400 |
| 8 | 132864 |
| 9 | 381024 |
| 10 | 1139200 |
| 11 | 2613600 |
| 12 | 6177600 |
| 13 | 12269400 |
| 14 | 24912384 |
| 15 | 44717400 |
| 16 | 81636352 |
| 17 | 135945600 |
| 18 | 229423104 |
| 19 | 360561024 |
| 20 | 572788800 |
| 21 | 859685400 |
| 22 | 1301766400 |
| 23 | 1881864600 |
| 24 | 2740725504 |
| 25 | 3840540000 |