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 | 2 |
| 3 | 4 |
| 4 | 8 |
| 5 | 24 |
| 6 | 48 |
| 7 | 192 |
| 8 | 384 |
| 9 | 1920 |
| 10 | 3840 |
| 11 | 23040 |
| 12 | 46080 |
| 13 | 322560 |
| 14 | 645120 |
| 15 | 5160960 |
| 16 | 10321920 |
| 17 | 92897280 |
| 18 | 185794560 |
| 19 | 1857945600 |
| 20 | 3715891200 |
| 21 | 40874803200 |
| 22 | 81749606400 |
| 23 | 980995276800 |
| 24 | 1961990553600 |
| 25 | 25505877196800 |
| 26 | 51011754393600 |
| 27 | 714164561510400 |
| 28 | 1428329123020800 |