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 | 2 |
| 2 | 4 |
| 3 | 12 |
| 4 | 48 |
| 5 | 160 |
| 6 | 720 |
| 7 | 3360 |
| 8 | 13440 |
| 9 | 80640 |
| 10 | 403200 |
| 11 | 2217600 |
| 12 | 13305600 |
| 13 | 69189120 |
| 14 | 484323840 |
| 15 | 2905943040 |
| 16 | 19372953600 |
| 17 | 131736084480 |
| 18 | 846874828800 |
| 19 | 6436248698880 |
| 20 | 42908324659200 |
| 21 | 337903056691200 |
| 22 | 2477955749068800 |
| 23 | 18997660742860800 |
| 24 | 151981285942886400 |