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) |
|---|---|
| 0 | 2 |
| 1 | 21 |
| 2 | 2905 |
| 3 | 281785 |
| 4 | 47740490 |
| 5 | 9178864590 |
| 6 | 8533159052845 |
| 7 | 1817562878255985 |
| 8 | 1801204812351681135 |
| 9 | 787408225243814333670 |