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 | 24 |
| 5 | 240 |
| 6 | 2240 |
| 7 | 21840 |
| 8 | 228480 |
| 9 | 2580480 |
| 10 | 31449600 |
| 11 | 412473600 |
| 12 | 5801241600 |
| 13 | 87178291200 |
| 14 | 1394852659200 |
| 15 | 23683435776000 |
| 16 | 425430061056000 |
| 17 | 8062248370176000 |
| 18 | 160770717499392000 |
| 19 | 3365514444644352000 |
| 20 | 73798027581358080000 |
| 21 | 1691677863018823680000 |
| 22 | 40464026199993876480000 |