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 | 17 |
| 3 | -721 |
| 4 | 58337 |
| 5 | -7657441 |
| 6 | 1482169457 |
| 7 | -396854618161 |
| 8 | 140415423261377 |
| 9 | -63432792091634881 |
| 10 | 35619694647751942097 |
| 11 | -24334169873267896659601 |
| 12 | 19872330538404158435859617 |