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 | 0 |
| 3 | 2 |
| 4 | 0 |
| 5 | 8 |
| 6 | 0 |
| 7 | 18 |
| 8 | 0 |
| 9 | 578 |
| 10 | 0 |
| 11 | -15460 |
| 12 | 0 |
| 13 | 1012512 |
| 14 | 0 |
| 15 | -81237604 |
| 16 | 0 |
| 17 | 8572174172 |
| 18 | 0 |
| 19 | -1139408178984 |
| 20 | 0 |
| 21 | 186543348044576 |
| 22 | 0 |
| 23 | -36888247922732008 |
| 24 | 0 |
| 25 | 8669441321229610968 |
| 26 | 0 |
| 27 | -2388740252077518073072 |
| 28 | 0 |
| 29 | 762715125987833507921408 |
| 30 | 0 |
| 31 | -279382350611903941569174000 |
| 32 | 0 |