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 | 1 |
| 3 | -23 |
| 4 | 263 |
| 5 | -133787 |
| 6 | 157009 |
| 7 | -16215071 |
| 8 | 2689453969 |
| 9 | -26893118531 |
| 10 | 5600751928169 |
| 11 | -3340626516019229 |
| 12 | 885646796787371 |
| 13 | -859202038021848149 |
| 14 | 2766671664340938282413 |
| 15 | -319473088311274492668499 |
| 16 | 436677987276721765221113 |
| 17 | -191960665849028069896950959123 |