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 | 0 |
| 1 | -1 |
| 2 | 26 |
| 3 | 18 |
| 4 | -272 |
| 5 | -1400 |
| 6 | -4032 |
| 7 | -7168 |
| 8 | -1024 |
| 9 | 55296 |
| 10 | 294400 |
| 11 | 1086976 |
| 12 | 3354624 |
| 13 | 9132032 |
| 14 | 22249472 |
| 15 | 47923200 |
| 16 | 85983232 |
| 17 | 99155968 |
| 18 | -102629376 |
| 19 | -1237712896 |
| 20 | -5688524800 |
| 21 | -20775960576 |
| 22 | -67868033024 |
| 23 | -207022456832 |
| 24 | -602167836672 |
| 25 | -1690304512000 |
| 26 | -4613767954432 |