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 | 28 |
| 2 | 120 |
| 3 | 496 |
| 4 | 8128 |
| 5 | 523776 |
| 6 | 2178540 |
| 7 | 33550336 |
| 8 | 142990848 |
| 9 | 459818240 |
| 10 | 1379454720 |
| 11 | 1476304896 |
| 12 | 8589869056 |
| 13 | 31998395520 |
| 14 | 43861478400 |
| 15 | 66433720320 |
| 16 | 137438691328 |
| 17 | 704575228896 |
| 18 | 30823866178560 |
| 19 | 181742883469056 |
| 20 | 6088728021160320 |
| 21 | 14942123276641920 |
| 22 | 20158185857531904 |