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) |
|---|---|
| 2 | -1 |
| 3 | 5 |
| 4 | -17 |
| 5 | -229 |
| 6 | 853 |
| 7 | 12113 |
| 8 | -46061 |
| 9 | -674761 |
| 10 | 38733269 |
| 11 | -150113729 |
| 12 | 8829861373 |
| 13 | 134484418361 |
| 14 | -525740249453 |
| 15 | -8058251350417 |
| 16 | 486561579496253 |
| 17 | -29557651813108141 |
| 18 | 116325817932650581 |
| 19 | -7111675770821993117 |
| 20 | -110606189396709847609 |