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 | 10 |
| 4 | 32 |
| 5 | 112 |
| 6 | 396 |
| 7 | 1416 |
| 8 | 5184 |
| 9 | 19424 |
| 10 | 73984 |
| 11 | 285056 |
| 12 | 1108848 |
| 13 | 4350816 |
| 14 | 17203008 |
| 15 | 68473504 |
| 16 | 274122752 |
| 17 | 1103014912 |
| 18 | 4458611968 |
| 19 | 18096793088 |
| 20 | 73724852224 |
| 21 | 301360575488 |
| 22 | 1235633545216 |
| 23 | 5080554352640 |
| 24 | 20943623880448 |
| 25 | 86541514460672 |
| 26 | 358386391051264 |