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 | -3 |
| 3 | -12 |
| 4 | -100 |
| 5 | -1749 |
| 6 | -47600 |
| 7 | -800681 |
| 8 | -39453535 |
| 9 | -1351201968 |
| 10 | -66984136299 |
| 11 | -2938096403400 |
| 12 | -235011452211680 |