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 | -3 |
| 2 | -12 |
| 3 | 78 |
| 4 | 1824 |
| 5 | 240 |
| 6 | -513120 |
| 7 | -5857680 |
| 8 | 196293120 |
| 9 | 6811964160 |
| 10 | -57818956800 |
| 11 | -8095402329600 |
| 12 | -83402198630400 |
| 13 | 10192670228889600 |
| 14 | 371764953132748800 |
| 15 | -11291351664942336000 |
| 16 | -1131884186768228352000 |