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 | 0 |
| 2 | 4 |
| 3 | 384 |
| 4 | 82944 |
| 5 | 32768000 |
| 6 | 20736000000 |
| 7 | 19271206305792 |
| 8 | 24759631762948096 |
| 9 | 42071440246337175552 |
| 10 | 91403961001574400000000 |
| 11 | 247248735803801600000000000 |
| 12 | 815050629127324260701847945216 |
| 13 | 3217014140995401936351315753959424 |