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) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 7136 |
| 3 | 12880512 |
| 4 | 61907282240 |
| 5 | 654044867816320 |
| 6 | 13334947538204224800 |
| 7 | 477979874685352308242176 |
| 8 | 28084174272553340151416556672 |
| 9 | 2561385146102672068174078977972480 |