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 | 16 |
| 4 | 1152 |
| 5 | 16640 |
| 6 | 140800 |
| 7 | 887040 |
| 8 | 4616192 |
| 9 | 20987904 |
| 10 | 86261760 |
| 11 | 327782400 |
| 12 | 1169653760 |
| 13 | 3964207104 |
| 14 | 12869828608 |
| 15 | 40285306880 |
| 16 | 122211532800 |
| 17 | 360794030080 |
| 18 | 1040028008448 |
| 19 | 2935426646016 |
| 20 | 8130951905280 |
| 21 | 22146344550400 |
| 22 | 59411980615680 |
| 23 | 157208570494976 |