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 | 2 |
| 3 | 1 |
| 4 | 8 |
| 5 | 27 |
| 6 | 0 |
| 7 | 211 |
| 8 | 500 |
| 9 | 0 |
| 10 | 5404 |
| 11 | 23137 |
| 12 | 0 |
| 13 | 269736 |
| 14 | 806856 |
| 15 | 0 |
| 16 | 10508986 |
| 17 | 43103947 |
| 18 | 0 |