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 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 5 |
| 6 | 16 |
| 7 | 41 |
| 8 | 154 |
| 9 | 560 |
| 10 | 2550 |
| 11 | 12404 |
| 12 | 69536 |
| 13 | 428698 |
| 14 | 2947229 |
| 15 | 22288540 |
| 16 | 185226859 |
| 17 | 1682006569 |
| 18 | 16635022967 |
| 19 | 178525323313 |