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) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 1 |
| 6 | 15 |
| 7 | 465 |
| 8 | 19355 |
| 9 | 1024380 |
| 10 | 66462606 |
| 11 | 5188453830 |
| 12 | 480413921130 |
| 13 | 52113376310985 |
| 14 | 6551246596501035 |
| 15 | 945313907253606891 |
| 16 | 155243722248524067795 |
| 17 | 28797220460586826422720 |