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 | 3 |
| 4 | 6 |
| 5 | 14 |
| 6 | 42 |
| 7 | 3810 |
| 8 | 318990 |
| 9 | 13243560 |
| 10 | 1108809240 |
| 11 | 1719507048 |
| 12 | 25330080090 |
| 13 | 271984504290 |