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 | 5 |
| 6 | 0 |
| 7 | 0 |
| 8 | 0 |
| 9 | 315 |
| 10 | 6300 |
| 11 | 0 |
| 12 | 0 |
| 13 | 150150 |
| 14 | 6306300 |
| 15 | 94594500 |
| 16 | 0 |
| 17 | 268017750 |
| 18 | 17689171500 |
| 19 | 549972423000 |
| 20 | 7332965640000 |
| 21 | 1283268987000 |
| 22 | 117632990475000 |
| 23 | 5681673439942500 |
| 24 | 155840185781280000 |
| 25 | 1961530116170625000 |
| 26 | 1606200062942475000 |