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 | 16 |
| 2 | 64 |
| 3 | 484 |
| 4 | 2704 |
| 5 | 17424 |
| 6 | 104976 |
| 7 | 652864 |
| 8 | 4000000 |
| 9 | 24681024 |
| 10 | 151782400 |
| 11 | 934891776 |
| 12 | 5754132736 |
| 13 | 35428274176 |
| 14 | 218096472064 |
| 15 | 1342706197504 |
| 16 | 8266039005184 |
| 17 | 50888705511424 |
| 18 | 313286601609216 |
| 19 | 1928696564957184 |
| 20 | 11873676328960000 |