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 | 1 |
| 2 | -6 |
| 3 | 210 |
| 4 | -17640 |
| 5 | 2693880 |
| 6 | -649479600 |
| 7 | 226750764240 |
| 8 | -108116216208000 |
| 9 | 67478689070432640 |
| 10 | -53382381970299782400 |
| 11 | 52192613508738839136000 |
| 12 | -61794396463636399635072000 |
| 13 | 87121906773549083421777792000 |
| 14 | -144222462676882552982237906688000 |