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 | 1 |
| 1 | 12 |
| 2 | 280 |
| 3 | 5544 |
| 4 | 102960 |
| 5 | 1847560 |
| 6 | 32449872 |
| 7 | 561632400 |
| 8 | 9617286240 |
| 9 | 163352435400 |
| 10 | 2756930576400 |
| 11 | 46290177201840 |
| 12 | 773942488394400 |
| 13 | 12893881856650704 |
| 14 | 214163336821292320 |
| 15 | 3547937446945842720 |