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 | 18 |
| 3 | -268 |
| 4 | 5580 |
| 5 | -149368 |
| 6 | 4887368 |
| 7 | -189010176 |
| 8 | 8434813760 |
| 9 | -426626153664 |
| 10 | 24118046539968 |
| 11 | -1507010218083456 |
| 12 | 103135804627122816 |
| 13 | -7672260068001952512 |
| 14 | 616407170000568900864 |
| 15 | -53192668792451354284032 |
| 16 | 4906864974307552234844160 |