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 | 0 |
| 5 | 0 |
| 6 | 396 |
| 7 | 6120 |
| 8 | 10934400 |
| 9 | 1225559160 |
| 10 | 130025295822240 |
| 11 | 252282619805005440 |
| 12 | 2209617218725251390961920 |
| 13 | 98758655816833727741298666240 |