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 | 0 |
| 3 | 0 |
| 4 | 2 |
| 5 | 6 |
| 6 | 36 |
| 7 | 248 |
| 8 | 2264 |
| 9 | 31754 |
| 10 | 710574 |
| 11 | 26501530 |
| 12 | 1712953820 |