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) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 12 |
| 5 | 24 |
| 6 | 48 |
| 7 | 240 |
| 8 | 720 |
| 9 | 5040 |
| 10 | 10080 |
| 11 | 20160 |
| 12 | 221760 |
| 13 | 665280 |
| 14 | 8648640 |
| 15 | 17297280 |
| 16 | 294053760 |
| 17 | 5587021440 |
| 18 | 27935107200 |
| 19 | 642507465600 |
| 20 | 1927522396800 |
| 21 | 13492656777600 |
| 22 | 26985313555200 |
| 23 | 782574093100800 |
| 24 | 24259796886124800 |