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) |
|---|---|
| 4 | 3 |
| 5 | 3 |
| 6 | 1 |
| 7 | 15 |
| 8 | 105 |
| 9 | 250 |
| 10 | 210 |
| 11 | 52 |
| 12 | 1 |
| 13 | 105 |
| 14 | 5460 |
| 15 | 105945 |
| 16 | 635265 |
| 17 | 1715455 |
| 18 | 2373345 |
| 19 | 1742445 |
| 20 | 640140 |
| 21 | 90262 |
| 22 | 1 |