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) |
|---|---|
| 2 | 15 |
| 3 | 135 |
| 4 | 1155 |
| 5 | 10395 |
| 6 | 135135 |
| 7 | 2297295 |
| 8 | 57432375 |
| 9 | 1003917915 |
| 10 | 25097947875 |