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 | 75 |
| 1 | 21875 |
| 2 | 5512500 |
| 3 | 1512630000 |
| 4 | 484041600000 |
| 5 | 184834742400000 |
| 6 | 84715923600000000 |
| 7 | 46534591303200000000 |
| 8 | 30489464221856640000000 |
| 9 | 23681690417572387200000000 |
| 10 | 21660852835272876825600000000 |
| 11 | 23175597788788462617600000000000 |
| 12 | 28817200450516396946227200000000000 |