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) |
|---|---|
| 5 | 1 |
| 6 | 30 |
| 7 | 630 |
| 8 | 11760 |
| 9 | 211680 |
| 10 | 3810240 |
| 11 | 69854400 |
| 12 | 1317254400 |
| 13 | 25686460800 |
| 14 | 519437318400 |
| 15 | 10908183686400 |
| 16 | 237996734976000 |
| 17 | 5394592659456000 |
| 18 | 126980411830272000 |
| 19 | 3101950060425216000 |
| 20 | 78582734864105472000 |
| 21 | 2062796790182768640000 |
| 22 | 56059536297908183040000 |