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 | 72 |
| 5 | 1440 |
| 6 | 35280 |
| 7 | 1058400 |
| 8 | 37376640 |
| 9 | 1520830080 |
| 10 | 70053984000 |
| 11 | 3603888288000 |
| 12 | 204806714112000 |
| 13 | 12742502111539200 |
| 14 | 861483843034214400 |
| 15 | 62887137880799232000 |
| 16 | 4929809613351727104000 |
| 17 | 413044721987184967680000 |