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 | 7 |
| 3 | -43 |
| 4 | 4489 |
| 5 | -49897 |
| 6 | 20130311 |
| 7 | -319053131 |
| 8 | 329796121169 |
| 9 | -62717244921977 |
| 10 | 14635852695795623 |
| 11 | -33233512260583073 |
| 12 | 149490010959849868177 |
| 13 | -3562767949848393597053 |