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 | 0 |
| 1 | -1 |
| 2 | 1 |
| 3 | -5 |
| 4 | -20 |
| 5 | 116 |
| 6 | -3741 |
| 7 | 8385 |
| 8 | -239785 |
| 9 | -59997896 |
| 10 | 1849037896 |
| 11 | -270896443865 |
| 12 | -16683000076735 |
| 13 | 2786836257692691 |
| 14 | -3148929681285740316 |
| 15 | 342115756927607927420 |
| 16 | -280251129922563291422645 |
| 17 | -804287518035141565236193151 |