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 | 6 |
| 1 | 30 |
| 2 | 210 |
| 3 | 1680 |
| 4 | 18480 |
| 5 | 277200 |
| 6 | 6098400 |
| 7 | 201247200 |
| 8 | 10263607200 |
| 9 | 821088576000 |
| 10 | 104278249152000 |
| 11 | 21168484577856000 |
| 12 | 6900925972381056000 |
| 13 | 3622986135500054400000 |
| 14 | 3068669256768546076800000 |
| 15 | 4197939543259371033062400000 |
| 16 | 9281644330146469354100966400000 |