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 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 5 |
| 6 | 20 |
| 7 | 56 |
| 8 | 276 |
| 9 | 2136 |
| 10 | 13756 |
| 11 | 148352 |
| 12 | 2727448 |
| 13 | 41044816 |
| 14 | 1056334024 |
| 15 | 46033137324 |