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) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 5 |
| 5 | 18 |
| 6 | 52 |
| 7 | 134 |
| 8 | 318 |
| 9 | 713 |
| 10 | 1531 |
| 11 | 3180 |
| 12 | 6432 |
| 13 | 12732 |
| 14 | 24756 |
| 15 | 47417 |
| 16 | 89665 |
| 17 | 167694 |
| 18 | 310628 |
| 19 | 570562 |
| 20 | 1040226 |
| 21 | 1883953 |
| 22 | 3391799 |
| 23 | 6073848 |
| 24 | 10824096 |
| 25 | 19204536 |
| 26 | 33936456 |