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) |
|---|---|
| 1 | 1 |
| 2 | -1 |
| 3 | 8 |
| 4 | 4 |
| 5 | -76 |
| 6 | 264 |
| 7 | -33 |
| 8 | 1248 |
| 9 | -9735 |
| 10 | 22080 |
| 11 | 456 |
| 12 | -32088 |
| 13 | 440448 |
| 14 | -2085096 |
| 15 | 3715440 |
| 16 | -9460 |
| 17 | 1216600 |
| 18 | -26297700 |
| 19 | 205444800 |
| 20 | -704121000 |
| 21 | 1087450320 |
| 22 | 274800 |
| 23 | -64995600 |
| 24 | 2073673920 |
| 25 | -23974142160 |
| 26 | 129203087760 |
| 27 | -354403429920 |
| 28 | 500558083200 |