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 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 24 |
| 5 | 120 |
| 6 | 720 |
| 7 | 3312 |
| 8 | 18688 |
| 9 | 127104 |
| 10 | 990208 |
| 11 | 8878016 |
| 12 | 89267712 |
| 13 | 789509184 |
| 14 | 7803741824 |
| 15 | 85447337472 |
| 16 | 1008717911040 |