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) |
|---|---|
| 1 | 1 |
| 2 | -3 |
| 3 | 16 |
| 4 | -124 |
| 5 | 1270 |
| 6 | -16243 |
| 7 | 249776 |
| 8 | -4494334 |
| 9 | 92716855 |
| 10 | -2158505443 |
| 11 | 55996266046 |
| 12 | -1602132913687 |
| 13 | 50124833578256 |
| 14 | -1702501170925098 |
| 15 | 62391472267252322 |
| 16 | -2453892459756494459 |
| 17 | 103101294099324376489 |
| 18 | -4608723131704380915202 |