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 | 1 |
| 1 | 6 |
| 2 | 48 |
| 3 | 420 |
| 4 | 3840 |
| 5 | 36036 |
| 6 | 344064 |
| 7 | 3325608 |
| 8 | 32440320 |
| 9 | 318704100 |
| 10 | 3148873728 |
| 11 | 31256180280 |
| 12 | 311452237824 |
| 13 | 3113596420200 |
| 14 | 31213674823680 |
| 15 | 313672599360720 |
| 16 | 3158823892156416 |
| 17 | 31870058661517860 |
| 18 | 322076161553203200 |
| 19 | 3259691964853493400 |
| 20 | 33034843349204336640 |
| 21 | 335189468043077792760 |