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 | 5 |
| 3 | 56 |
| 4 | 1080 |
| 5 | 31680 |
| 6 | 1310400 |
| 7 | 72576000 |
| 8 | 5181926400 |
| 9 | 463325184000 |
| 10 | 50697529344000 |
| 11 | 6663103856640000 |
| 12 | 1035678099456000000 |
| 13 | 187913434365296640000 |
| 14 | 39357424864287129600000 |
| 15 | 9424067526124476825600000 |
| 16 | 2558178330075402338304000000 |
| 17 | 781407199004850168791040000000 |