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 | -2 |
| 3 | 9 |
| 4 | -64 |
| 5 | 560 |
| 6 | -5370 |
| 7 | 53788 |
| 8 | -555864 |
| 9 | 5957685 |
| 10 | -66459200 |
| 11 | 763983132 |
| 12 | -8919566196 |
| 13 | 105678848821 |
| 14 | -1286858544734 |