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 | 2 |
| 2 | -10 |
| 3 | 84 |
| 4 | -868 |
| 5 | 9872 |
| 6 | -121392 |
| 7 | 1522000 |
| 8 | -20885744 |
| 9 | 249139392 |
| 10 | -4898915424 |
| 11 | -6811333312 |
| 12 | -4215314380800 |
| 13 | -213186664776192 |
| 14 | -15944754147807232 |
| 15 | -1207550934725368320 |
| 16 | -100056122156079206144 |
| 17 | -8876452703027927096320 |