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 | 4 |
| 5 | 18 |
| 6 | 33 |
| 7 | 161 |
| 8 | 433 |
| 9 | 1705 |
| 10 | 10789 |
| 11 | 29157 |
| 12 | 88720 |
| 13 | 490289 |
| 14 | 1881309 |
| 15 | 4731356 |
| 16 | 17455195 |
| 17 | 36595263 |
| 18 | 178053588 |
| 19 | 405917904 |
| 20 | 3256229459 |