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 | 2 |
| 2 | 7 |
| 3 | 31 |
| 4 | 157 |
| 5 | 3907 |
| 6 | 19531 |
| 7 | 2441407 |
| 8 | 12207031 |
| 9 | 61035157 |
| 10 | 305175781 |
| 11 | 9313225746154785157 |
| 12 | 177635683940025046467781066894531 |