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 | 1 |
| 1 | 2 |
| 2 | 13 |
| 3 | 289 |
| 4 | 13814 |
| 5 | 1795898 |
| 6 | 265709592 |
| 7 | 70163924440 |
| 8 | 20610999526800 |
| 9 | 9097511018219760 |
| 10 | 6845834489829830144 |