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 | 10 |
| 2 | 60 |
| 3 | 1170 |
| 4 | 114660 |
| 5 | 72602880 |
| 6 | 668304000 |
| 7 | 714954240 |
| 8 | 1307124000 |
| 9 | 1381161600 |
| 10 | 2701389600 |
| 11 | 8052817920 |
| 12 | 10181689600 |
| 13 | 643773312000 |
| 14 | 1330464844800 |
| 15 | 2015156183040 |
| 16 | 3522876144480 |
| 17 | 15462510336000 |
| 18 | 23885971200000 |
| 19 | 702577007193600 |
| 20 | 908714417345280 |