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 | 4 |
| 2 | 24 |
| 3 | 192 |
| 4 | 2112 |
| 5 | 32640 |
| 6 | 718080 |
| 7 | 22665216 |
| 8 | 1031276544 |
| 9 | 67849629696 |
| 10 | 6468240187392 |
| 11 | 894839431299072 |
| 12 | 179851071814434816 |
| 13 | 52561241074964496384 |
| 14 | 22351071118387029737472 |
| 15 | 13837189739906569661841408 |