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 | 20 |
| 2 | -482 |
| 3 | -44920 |
| 4 | 376972 |
| 5 | 166017200 |
| 6 | 1657897480 |
| 7 | -845405072800 |
| 8 | -27143960497520 |
| 9 | 5422298983726400 |
| 10 | 323914738103841760 |
| 11 | -41346382274390012800 |
| 12 | -3969548434571273011520 |
| 13 | 358219141300718435244800 |
| 14 | 52679225176808585054984320 |
| 15 | -3369705453245099537303104000 |