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 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 48 |
| 6 | 512 |
| 7 | 1440 |
| 8 | 40512 |
| 9 | 385072 |
| 10 | 3154650 |
| 11 | 106906168 |
| 12 | 3197817022 |
| 13 | 82924866213 |
| 14 | 4025168862425 |
| 15 | 127854811616691 |