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 | 0 |
| 4 | 0 |
| 5 | 2 |
| 6 | 5 |
| 7 | 21 |
| 8 | 58 |
| 9 | 194 |
| 10 | 570 |
| 11 | 1790 |
| 12 | 5434 |
| 13 | 16924 |
| 14 | 52362 |
| 15 | 163784 |
| 16 | 512670 |
| 17 | 1614406 |
| 18 | 5096314 |
| 19 | 16150180 |