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 | 4 |
| 1 | 8 |
| 2 | 48 |
| 3 | 400 |
| 4 | 3920 |
| 5 | 42336 |
| 6 | 487872 |
| 7 | 5889312 |
| 8 | 73616400 |
| 9 | 945561760 |
| 10 | 12412647104 |
| 11 | 165878102208 |
| 12 | 2249987591488 |
| 13 | 30906422960000 |
| 14 | 429157758816000 |
| 15 | 6015361252737600 |
| 16 | 85011208292365200 |
| 17 | 1210159553338375200 |
| 18 | 17338543308064440000 |
| 19 | 249857534618318088000 |