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 | 1 |
| 3 | 2 |
| 4 | 3 |
| 5 | 8 |
| 6 | 17 |
| 7 | 56 |
| 8 | 151 |
| 9 | 584 |
| 10 | 1893 |
| 11 | 8360 |
| 12 | 31499 |
| 13 | 155720 |
| 14 | 666169 |
| 15 | 3633704 |
| 16 | 17351967 |
| 17 | 103284296 |
| 18 | 543441005 |
| 19 | 3499082408 |
| 20 | 20079329875 |
| 21 | 138860069192 |
| 22 | 861908850561 |
| 23 | 6364334129192 |
| 24 | 42439075349543 |
| 25 | 332934707138888 |
| 26 | 2371469004695797 |
| 27 | 19681714722718376 |