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 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 6 |
| 5 | 24 |
| 6 | 78 |
| 7 | 368 |
| 8 | 1902 |
| 9 | 11062 |
| 10 | 77426 |
| 11 | 692414 |
| 12 | 6261624 |
| 13 | 68889928 |
| 14 | 764874856 |
| 15 | 9274470290 |