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 | 6 |
| 3 | 60 |
| 4 | 90 |
| 5 | 120 |
| 6 | 36720 |
| 7 | 73440 |
| 8 | 12646368 |
| 9 | 22276800 |
| 10 | 44553600 |
| 11 | 126463680 |
| 12 | 133660800 |
| 13 | 252927360 |
| 14 | 758782080 |
| 15 | 4201148160 |
| 16 | 8402296320 |
| 17 | 28770487200 |
| 18 | 287704872000 |
| 19 | 575409744000 |