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 | 2 |
| 3 | 6 |
| 4 | 35 |
| 5 | 251 |
| 6 | 2602 |
| 7 | 30900 |
| 8 | 400818 |
| 9 | 5401599 |
| 10 | 74617105 |
| 11 | 1047497078 |
| 12 | 14888851869 |