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 | -3 |
| 2 | 13 |
| 3 | -91 |
| 4 | 291 |
| 5 | -1187 |
| 6 | 18017 |
| 7 | -114949 |
| 8 | 122399 |
| 9 | -27857449 |
| 10 | 118047751 |
| 11 | -18228890369 |
| 12 | 594111334397 |
| 13 | -17200311140979 |
| 14 | 773613644762857 |
| 15 | -398027494487496919 |
| 16 | 7730820144185428909 |
| 17 | -6072430940814524211839 |