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 | 41 |
| 2 | 1640 |
| 3 | 65600 |
| 4 | 2623180 |
| 5 | 104894400 |
| 6 | 4194464820 |
| 7 | 167726145600 |
| 8 | 6706948607580 |
| 9 | 268194081870000 |
| 10 | 10724409825744420 |
| 11 | 428842296999090000 |
| 12 | 17148329715447559980 |
| 13 | 685718769084764781600 |
| 14 | 27420176663127165184020 |