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 | -1 |
| 2 | -4 |
| 3 | -6 |
| 4 | 96 |
| 5 | 1104 |
| 6 | 2016 |
| 7 | -112176 |
| 8 | -1718784 |
| 9 | -642816 |
| 10 | 437031936 |
| 11 | 7656021504 |
| 12 | -24274059264 |
| 13 | -3939918299136 |
| 14 | -72733516959744 |
| 15 | 699443277686784 |
| 16 | 67781787782086656 |
| 17 | 1236409075147014144 |
| 18 | -25430445045847425024 |