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 | 0 |
| 2 | -2 |
| 3 | -8 |
| 4 | -36 |
| 5 | -224 |
| 6 | -1880 |
| 7 | -19872 |
| 8 | -251888 |
| 9 | -3712256 |
| 10 | -62286624 |
| 11 | -1171487360 |
| 12 | -24402416192 |
| 13 | -557542291968 |
| 14 | -13861636770176 |
| 15 | -372514645389824 |
| 16 | -10759590258589440 |
| 17 | -332386419622387712 |