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 | 4 |
| 3 | 54 |
| 4 | 768 |
| 5 | 75000 |
| 6 | 233280 |
| 7 | 592950960 |
| 8 | 5284823040 |
| 9 | 1735643790720 |
| 10 | 5670000000000 |
| 11 | 1035338990313196800 |
| 12 | 17163493362892800 |
| 13 | 145077660657859734604800 |
| 14 | 9653278129532887449600 |