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 | 2 |
| 3 | -16 |
| 4 | -126 |
| 5 | -498 |
| 6 | -880 |
| 7 | 3432 |
| 8 | 37762 |
| 9 | 175916 |
| 10 | 411502 |
| 11 | -710752 |
| 12 | -12482928 |
| 13 | -66911830 |
| 14 | -190616760 |
| 15 | 70959984 |
| 16 | 4208145282 |
| 17 | 26042918836 |
| 18 | 86794308524 |
| 19 | 50521487200 |
| 20 | -1397839172626 |
| 21 | -10176550581570 |
| 22 | -38838971577536 |
| 23 | -51156092490048 |
| 24 | 443929768322704 |