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 | 2 |
| 2 | 4 |
| 3 | 8 |
| 4 | 88 |
| 5 | 252 |
| 6 | 2772 |
| 7 | 27872 |
| 8 | 2112 |
| 9 | 4224 |
| 10 | 8448 |
| 11 | 44544 |
| 12 | 48384 |
| 13 | 2977792 |
| 14 | 27011072 |
| 15 | 405504 |
| 16 | 4091904 |
| 17 | 441606144 |
| 18 | 405909504 |
| 19 | 886898688 |
| 20 | 677707776 |
| 21 | 4285005824 |
| 22 | 276486684672 |
| 23 | 21128282112 |
| 24 | 633498894336 |
| 25 | 2701312131072 |
| 26 | 6739855589376 |
| 27 | 29142024192 |
| 28 | 65892155129856 |