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 | 1 |
| 2 | 1 |
| 3 | 3 |
| 4 | 12 |
| 5 | 140 |
| 6 | 3950 |
| 7 | 263707 |
| 8 | 42285095 |
| 9 | 16825391023 |
| 10 | 17095967464466 |
| 11 | 45375565948693336 |