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 | 4 |
| 2 | 5 |
| 3 | 17 |
| 4 | 53 |
| 5 | 250 |
| 6 | 1404 |
| 7 | 9013 |
| 8 | 58608 |
| 9 | 401614 |
| 10 | 2908740 |
| 11 | 21832530 |