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) |
|---|---|
| 3 | 6 |
| 4 | 24 |
| 5 | 180 |
| 6 | 1320 |
| 7 | 11130 |
| 8 | 103824 |
| 9 | 1067976 |
| 10 | 12014640 |
| 11 | 146845710 |
| 12 | 1938363240 |
| 13 | 27489515196 |
| 14 | 416924313624 |
| 15 | 6734931220290 |
| 16 | 115455963776160 |
| 17 | 2093601476474640 |
| 18 | 40040128237577184 |
| 19 | 805513168073611926 |