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 | 1 |
| 5 | 1 |
| 6 | 5 |
| 7 | 8 |
| 8 | 42 |
| 9 | 146 |
| 10 | 956 |
| 11 | 6643 |
| 12 | 65921 |
| 13 | 818448 |
| 14 | 13442572 |
| 15 | 287665498 |
| 16 | 8099980771 |
| 17 | 300760170216 |
| 18 | 14791653463768 |
| 19 | 967055338887805 |
| 20 | 84368806391412395 |
| 21 | 9855854129239183783 |
| 22 | 1546801291978378704267 |