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 | 0 |
| 6 | 0 |
| 7 | 1 |
| 8 | 3 |
| 9 | 9 |
| 10 | 21 |
| 11 | 51 |
| 12 | 117 |
| 13 | 262 |
| 14 | 598 |
| 15 | 1307 |
| 16 | 2987 |
| 17 | 6456 |
| 18 | 14752 |
| 19 | 31859 |
| 20 | 72839 |
| 21 | 157611 |
| 22 | 360472 |
| 23 | 782802 |
| 24 | 1791140 |
| 25 | 3904323 |
| 26 | 8936996 |
| 27 | 19553272 |