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 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 14 |
| 5 | 41 |
| 6 | 125 |
| 7 | 393 |
| 8 | 1265 |
| 9 | 4147 |
| 10 | 13798 |
| 11 | 46476 |
| 12 | 158170 |
| 13 | 543050 |
| 14 | 1878670 |
| 15 | 6542330 |
| 16 | 22915999 |
| 17 | 80682987 |
| 18 | 285378270 |
| 19 | 1013564805 |
| 20 | 3613262795 |
| 21 | 12924536005 |
| 22 | 46373266470 |
| 23 | 166856922125 |
| 24 | 601928551824 |
| 25 | 2176616383346 |
| 26 | 7888184659826 |
| 27 | 28645799759632 |
| 28 | 104224861693855 |