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 | -6 |
| 3 | -10 |
| 4 | 66 |
| 5 | 60 |
| 6 | -750 |
| 7 | -236 |
| 8 | 8682 |
| 9 | -2098 |
| 10 | -100792 |
| 11 | 80286 |
| 12 | 1162458 |
| 13 | -1603412 |
| 14 | -13225764 |
| 15 | 26767020 |
| 16 | 147428498 |
| 17 | -409582818 |
| 18 | -1596563202 |
| 19 | 5941802122 |
| 20 | 16587101544 |
| 21 | -83014131140 |
| 22 | -161717252990 |
| 23 | 1126247965980 |
| 24 | 1411774064970 |
| 25 | -14905602076350 |