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 | 4 |
| 3 | 24 |
| 4 | 192 |
| 5 | 4320 |
| 6 | 51840 |
| 7 | 120960 |
| 8 | 29030400 |
| 9 | 65318400 |
| 10 | 145152000 |
| 11 | 6706022400 |
| 12 | 160944537600 |
| 13 | 8717829120000 |
| 14 | 6590678814720000 |
| 15 | 14122883174400000 |
| 16 | 30128817438720000 |
| 17 | 2112783322890240000 |
| 18 | 2662106986841702400000 |