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 | 6 |
| 6 | 0 |
| 7 | 10 |
| 8 | 48 |
| 9 | 32 |
| 10 | 0 |
| 11 | 94 |
| 12 | 344 |
| 13 | 370 |
| 14 | 0 |
| 15 | 1268 |
| 16 | 4608 |
| 17 | 3856 |
| 18 | 0 |
| 19 | 13798 |
| 20 | 55960 |
| 21 | 50090 |
| 22 | 0 |
| 23 | 182362 |
| 24 | 721952 |
| 25 | 690496 |
| 26 | 0 |
| 27 | 2485592 |
| 28 | 9586984 |
| 29 | 9256746 |
| 30 | 0 |
| 31 | 34636834 |
| 32 | 135335936 |
| 33 | 130150588 |
| 34 | 0 |
| 35 | 493452348 |
| 36 | 1908875264 |
| 37 | 1857293524 |
| 38 | 0 |
| 39 | 7049188508 |
| 40 | 27603824928 |