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 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 2 |
| 6 | 3 |
| 7 | 7 |
| 8 | 21 |
| 9 | 49 |
| 10 | 165 |
| 11 | 552 |
| 12 | 2176 |
| 13 | 9988 |
| 14 | 46972 |
| 15 | 253293 |
| 16 | 1388705 |
| 17 | 8053393 |
| 18 | 48266466 |
| 19 | 294130458 |