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 | 2 |
| 4 | 4 |
| 5 | 10 |
| 6 | 24 |
| 7 | 66 |
| 8 | 174 |
| 9 | 504 |
| 10 | 1406 |
| 11 | 4210 |
| 12 | 12198 |
| 13 | 37378 |
| 14 | 111278 |
| 15 | 346846 |
| 16 | 1053874 |
| 17 | 3328188 |
| 18 | 10274466 |
| 19 | 32786630 |
| 20 | 102511418 |
| 21 | 329903058 |
| 22 | 1042277722 |
| 23 | 3377919260 |
| 24 | 10765024432 |
| 25 | 35095839848 |
| 26 | 112670468128 |
| 27 | 369192702554 |
| 28 | 1192724674590 |
| 29 | 3925446804750 |