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 | 6 |
| 5 | 21 |
| 6 | 91 |
| 7 | 462 |
| 8 | 2646 |
| 9 | 16841 |
| 10 | 117931 |
| 11 | 900922 |
| 12 | 7456086 |
| 13 | 66453661 |
| 14 | 634585771 |
| 15 | 6463837382 |
| 16 | 69955114326 |
| 17 | 801626558481 |
| 18 | 9696295037611 |
| 19 | 123457062745842 |
| 20 | 1650499351041366 |
| 21 | 23116291464379301 |
| 22 | 338474628835617451 |