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 | -5 |
| 2 | 35 |
| 3 | -315 |
| 4 | 3345 |
| 5 | -40845 |
| 6 | 562275 |
| 7 | -8575875 |
| 8 | 143273025 |
| 9 | -2598830325 |
| 10 | 50790003075 |
| 11 | -1062924352875 |
| 12 | 23699584148625 |
| 13 | -560468936152125 |
| 14 | 14004884930911875 |
| 15 | -368541883096261875 |
| 16 | 10183347536828090625 |