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 | 1 |
| 2 | 4 |
| 3 | 30 |
| 4 | 384 |
| 5 | 7560 |
| 6 | 228960 |
| 7 | 10306800 |
| 8 | 685399680 |
| 9 | 66490865280 |
| 10 | 9316160179200 |
| 11 | 1866087527673600 |
| 12 | 529244914160793600 |
| 13 | 210621677079215001600 |
| 14 | 116661392964364363315200 |
| 15 | 89281569344544938769408000 |
| 16 | 93799600948326479830880256000 |