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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 1 |
| 6 | 0 |
| 7 | 6 |
| 8 | 0 |
| 9 | 32 |
| 10 | 0 |
| 11 | 176 |
| 12 | 0 |
| 13 | 952 |
| 14 | 0 |
| 15 | 5302 |
| 16 | 0 |
| 17 | 29960 |
| 18 | 0 |
| 19 | 172536 |
| 20 | 0 |
| 21 | 1007575 |
| 22 | 0 |
| 23 | 5959656 |
| 24 | 0 |
| 25 | 35622384 |
| 26 | 0 |
| 27 | 214875104 |
| 28 | 0 |
| 29 | 1306303424 |
| 30 | 0 |
| 31 | 7995896502 |
| 32 | 0 |
| 33 | 49236826080 |
| 34 | 0 |
| 35 | 304799714960 |
| 36 | 0 |
| 37 | 1895785216039 |
| 38 | 0 |
| 39 | 11841367945110 |
| 40 | 0 |
| 41 | 74245791718824 |