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 | 2 |
| 2 | 4 |
| 3 | 12 |
| 4 | 66 |
| 5 | 735 |
| 6 | 18808 |
| 7 | 1231170 |
| 8 | 223521350 |
| 9 | 119000455681 |
| 10 | 193166954325425 |
| 11 | 983670413713595700 |