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 | 21 |
| 2 | 217 |
| 3 | 3937 |
| 4 | 1040257 |
| 5 | 1073602561 |
| 6 | 68718821377 |
| 7 | 1125897758834689 |
| 8 | 4951760154835678088235319297 |
| 9 | 1427247692705959880439315947500961989719490561 |