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 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 120 |
| 7 | 840 |
| 8 | 6720 |
| 9 | 60480 |
| 10 | 604800 |
| 11 | 6652800 |
| 12 | 73180800 |
| 13 | 951350400 |
| 14 | 13318905600 |
| 15 | 199783584000 |
| 16 | 3196537344000 |
| 17 | 54341134848000 |
| 18 | 983080530432000 |
| 19 | 18678530078208000 |
| 20 | 373570601564160000 |
| 21 | 7844982632847360000 |
| 22 | 172589617922641920000 |
| 23 | 3969561212220764160000 |