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 | 24 |
| 4 | 630 |
| 5 | 52800 |
| 6 | 11381760 |
| 7 | 6738443712 |
| 8 | 10487895163200 |
| 9 | 43294107630090240 |
| 10 | 469590163875486482400 |
| 11 | 13388418681612808458240000 |
| 12 | 1001088091286168023193223168000 |
| 13 | 196239953628635168336022309340569600 |