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 | 1 |
| 4 | 3 |
| 5 | 7 |
| 6 | 24 |
| 7 | 93 |
| 8 | 434 |
| 9 | 2110 |
| 10 | 10957 |
| 11 | 58713 |
| 12 | 321576 |
| 13 | 1792133 |
| 14 | 10131027 |
| 15 | 57949430 |
| 16 | 334970205 |
| 17 | 1953890318 |
| 18 | 11489753730 |
| 19 | 68054102361 |
| 20 | 405715557048 |