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 | 3 |
| 4 | 10 |
| 5 | 44 |
| 6 | 238 |
| 7 | 1650 |
| 8 | 14512 |
| 9 | 163341 |
| 10 | 2360719 |
| 11 | 43944974 |
| 12 | 1055019099 |
| 13 | 32664984238 |
| 14 | 1303143553205 |
| 15 | 66900392672168 |
| 16 | 4413439778321689 |