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 | 3 |
| 3 | 16 |
| 4 | 126 |
| 5 | 2104 |
| 6 | 78660 |
| 7 | 5705431 |
| 8 | 820373528 |
| 9 | 239372827502 |
| 10 | 141301759543525 |
| 11 | 168080053760638246 |
| 12 | 403684916425998696873 |