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 | 4 |
| 3 | 50 |
| 4 | 189 |
| 5 | 1863 |
| 6 | 10449 |
| 7 | 447849 |
| 8 | 4449249 |
| 9 | 5745249 |
| 10 | 3606422049 |
| 11 | 16554218751 |
| 12 | 105265530369 |
| 13 | 1957645712385 |