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 | 3 |
| 1 | 6 |
| 2 | 16 |
| 3 | 56 |
| 4 | 216 |
| 5 | 856 |
| 6 | 3416 |
| 7 | 13656 |
| 8 | 54616 |
| 9 | 218456 |
| 10 | 873816 |
| 11 | 3495256 |
| 12 | 13981016 |
| 13 | 55924056 |
| 14 | 223696216 |
| 15 | 894784856 |
| 16 | 3579139416 |
| 17 | 14316557656 |
| 18 | 57266230616 |
| 19 | 229064922456 |
| 20 | 916259689816 |