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 | 0 |
| 3 | 1 |
| 4 | 2 |
| 5 | 4 |
| 6 | 15 |
| 7 | 58 |
| 8 | 360 |
| 9 | 2793 |
| 10 | 28761 |
| 11 | 369545 |
| 12 | 5914974 |
| 13 | 116089531 |
| 14 | 2816695796 |