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 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 7 |
| 5 | 32 |
| 6 | 184 |
| 7 | 1268 |
| 8 | 10186 |
| 9 | 93356 |
| 10 | 960646 |
| 11 | 10959452 |
| 12 | 137221954 |
| 13 | 1870087808 |
| 14 | 27548231008 |
| 15 | 436081302248 |
| 16 | 7380628161076 |
| 17 | 132975267434552 |
| 18 | 2540593483517404 |
| 19 | 51299775805464824 |
| 20 | 1091447620966600804 |
| 21 | 24401984084483685248 |
| 22 | 571907754141520643296 |