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 | 4 |
| 5 | 4 |
| 6 | 0 |
| 7 | 20 |
| 8 | 48 |
| 9 | 80 |
| 10 | 0 |
| 11 | 94 |
| 12 | 344 |
| 13 | 424 |
| 14 | 0 |
| 15 | 1096 |
| 16 | 4864 |
| 17 | 3856 |
| 18 | 0 |
| 19 | 16444 |
| 20 | 52432 |
| 21 | 65248 |
| 22 | 0 |
| 23 | 182362 |
| 24 | 720928 |
| 25 | 671104 |
| 26 | 0 |
| 27 | 4152320 |
| 28 | 11156656 |
| 29 | 9256396 |
| 30 | 0 |
| 31 | 34636834 |
| 32 | 135397376 |
| 33 | 130150588 |
| 34 | 0 |
| 35 | 533834992 |
| 36 | 2773200896 |
| 37 | 1857304312 |
| 38 | 0 |
| 39 | 7065319328 |
| 40 | 27541477824 |
| 41 | 26817356776 |