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 | 5 |
| 1 | 140 |
| 2 | 2016 |
| 3 | 21120 |
| 4 | 183040 |
| 5 | 1397760 |
| 6 | 9748480 |
| 7 | 63504384 |
| 8 | 392232960 |
| 9 | 2321285120 |
| 10 | 13264486400 |
| 11 | 73610035200 |
| 12 | 398475657216 |
| 13 | 2111580405760 |
| 14 | 10984378859520 |
| 15 | 56221121904640 |
| 16 | 283661115064320 |
| 17 | 1413061420253184 |
| 18 | 6959221409054720 |