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 | 0 |
| 4 | 2 |
| 5 | 4 |
| 6 | 19 |
| 7 | 84 |
| 8 | 821 |
| 9 | 12485 |
| 10 | 343572 |
| 11 | 16164685 |
| 12 | 1289300669 |