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 | -264 |
| 2 | 61128 |
| 3 | -14107296 |
| 4 | 3255470952 |
| 5 | -751247454384 |
| 6 | 173361309784992 |
| 7 | -40005651284526912 |
| 8 | 9231887649122522280 |
| 9 | -2130392752758423726312 |
| 10 | 491619206548389935051568 |
| 11 | -113448303808924351510423008 |
| 12 | 26179851123971817380111236128 |