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 | 3 |
| 3 | 6 |
| 4 | 18 |
| 5 | 206 |
| 6 | 7888299 |
| 7 | 8112499583888855378066 |
| 8 | 42287533217833953489054778023401252726576585396037133766 |