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) |
|---|---|
| 0 | 1 |
| 1 | 80 |
| 2 | 5616 |
| 3 | 378880 |
| 4 | 25108976 |
| 5 | 1647924480 |
| 6 | 107513168896 |
| 7 | 6986714808320 |
| 8 | 452774526525936 |
| 9 | 29282607270465280 |
| 10 | 1890903981075228416 |
| 11 | 121957594044379545600 |
| 12 | 7858392761937306551296 |
| 13 | 505967049989822738186240 |
| 14 | 32556176323125901615005696 |
| 15 | 2093691733876474661699584000 |