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 | 3 |
| 2 | 14 |
| 3 | 342 |
| 4 | 5256 |
| 5 | 252360 |
| 6 | 7950960 |
| 7 | 582346800 |
| 8 | 30400755840 |
| 9 | 3055726477440 |
| 10 | 234650484230400 |
| 11 | 30479146156166400 |
| 12 | 3193083216360576000 |
| 13 | 515174657767010841600 |
| 14 | 69927761804930559129600 |
| 15 | 13622234004598726450944000 |
| 16 | 2307722078006148475736064000 |