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 | 1 |
| 5 | 4 |
| 6 | 13 |
| 7 | 34 |
| 8 | 82 |
| 9 | 185 |
| 10 | 403 |
| 11 | 853 |
| 12 | 1777 |
| 13 | 3656 |
| 14 | 7465 |
| 15 | 15156 |
| 16 | 30659 |
| 17 | 61850 |
| 18 | 124548 |
| 19 | 250456 |
| 20 | 503158 |