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 | 6 |
| 4 | 48 |
| 5 | 240 |
| 6 | 960 |
| 7 | 3360 |
| 8 | 10752 |
| 9 | 32256 |
| 10 | 92160 |
| 11 | 253440 |
| 12 | 675840 |
| 13 | 1757184 |
| 14 | 4472832 |
| 15 | 11182080 |
| 16 | 27525120 |
| 17 | 66846720 |
| 18 | 160432128 |
| 19 | 381026304 |
| 20 | 896532480 |
| 21 | 2091909120 |
| 22 | 4844421120 |
| 23 | 11142168576 |
| 24 | 25467813888 |
| 25 | 57881395200 |
| 26 | 130862284800 |
| 27 | 294440140800 |
| 28 | 659545915392 |