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 | 0 |
| 3 | 513 |
| 4 | 61440 |
| 5 | 9665625 |
| 6 | 2173796352 |
| 7 | 678117659345 |
| 8 | 281470681743360 |
| 9 | 150094436937708753 |
| 10 | 99999989760000000000 |
| 11 | 81402748802521459701993 |
| 12 | 79496847166870496697384960 |
| 13 | 91733330190787463785195879433 |