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 | -6 |
| 2 | 48 |
| 3 | -300 |
| 4 | 2316 |
| 5 | -14916 |
| 6 | 112188 |
| 7 | -738660 |
| 8 | 5450556 |
| 9 | -36474276 |
| 10 | 265397628 |
| 11 | -1797317220 |
| 12 | 12944017596 |
| 13 | -88431340836 |
| 14 | 632080079868 |
| 15 | -4346196394980 |
| 16 | 30893559749436 |
| 17 | -213433808338596 |
| 18 | 1510963317814908 |