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 | 1 |
| 5 | 4 |
| 6 | 30 |
| 7 | 317 |
| 8 | 5511 |
| 9 | 165165 |
| 10 | 8932499 |
| 11 | 870814993 |
| 12 | 153082769374 |
| 13 | 48887756906623 |