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 | 4 |
| 3 | 32 |
| 4 | 400 |
| 5 | 6912 |
| 6 | 153664 |
| 7 | 4194304 |
| 8 | 136048896 |
| 9 | 5120000000 |
| 10 | 219503494144 |
| 11 | 10567230160896 |
| 12 | 564668382613504 |
| 13 | 33174037869887488 |
| 14 | 2125764000000000000 |
| 15 | 147573952589676412928 |
| 16 | 11034809241396899282944 |
| 17 | 884295678882933431599104 |
| 18 | 75613185918270483380568064 |