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 | 6 |
| 2 | 135 |
| 3 | 1735 |
| 4 | 4902 |
| 5 | 65260 |
| 6 | 963024 |
| 7 | 82599811 |
| 8 | 175820910 |
| 9 | 1270311937 |
| 10 | 20717271655 |
| 11 | 225023890967 |
| 12 | 1479132847647 |
| 13 | 5547233660249 |