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 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 20 |
| 6 | 82 |
| 7 | 252 |
| 8 | 1074 |
| 9 | 7912 |
| 10 | 39552 |
| 11 | 152680 |
| 12 | 776094 |
| 13 | 5550310 |
| 14 | 30026848 |
| 15 | 108376910 |