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 | 7 |
| 3 | 31 |
| 4 | 219 |
| 5 | 2134 |
| 6 | 30768 |
| 7 | 1658440 |
| 8 | 3685688857 |
| 9 | 105981863625149 |