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 | 0 |
| 1 | 9 |
| 2 | 272 |
| 3 | 6585 |
| 4 | 65568 |
| 5 | 390665 |
| 6 | 1679664 |
| 7 | 5764857 |
| 8 | 16777280 |
| 9 | 43046793 |
| 10 | 100000080 |
| 11 | 214358969 |
| 12 | 429981792 |
| 13 | 815730825 |
| 14 | 1475789168 |
| 15 | 2562890745 |
| 16 | 4294967424 |
| 17 | 6975757577 |
| 18 | 11019960720 |
| 19 | 16983563193 |
| 20 | 25600000160 |
| 21 | 37822859529 |
| 22 | 54875873712 |