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 | 1 |
| 3 | 1 |
| 4 | 4 |
| 5 | 8 |
| 6 | 16 |
| 7 | 192 |
| 8 | 3072 |
| 9 | 55296 |
| 10 | 110592 |
| 11 | 442368 |
| 12 | 13271040 |
| 13 | 477757440 |
| 14 | 19110297600 |
| 15 | 802632499200 |
| 16 | 1605264998400 |
| 17 | 6421059993600 |
| 18 | 12842119987200 |
| 19 | 770527199232000 |
| 20 | 50854795149312000 |
| 21 | 3559835660451840000 |