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 | 1 |
| 1 | -60 |
| 2 | 15120 |
| 3 | -8648640 |
| 4 | 8821612800 |
| 5 | -14079294028800 |
| 6 | 32382376266240000 |
| 7 | -101421602465863680000 |
| 8 | 415017197290314178560000 |
| 9 | -2149789081963827444940800000 |
| 10 | 13750050968240640337841356800000 |
| 11 | -106425394494182556214892101632000000 |
| 12 | 980390734080409707851586040233984000000 |