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 | 1 |
| 4 | 2 |
| 5 | 5 |
| 6 | 12 |
| 7 | 29 |
| 8 | 73 |
| 9 | 185 |
| 10 | 475 |
| 11 | 1231 |
| 12 | 3232 |
| 13 | 8506 |
| 14 | 22565 |
| 15 | 60077 |
| 16 | 160629 |
| 17 | 430724 |
| 18 | 1158502 |
| 19 | 3122949 |
| 20 | 8437289 |
| 21 | 22836877 |
| 22 | 61918923 |
| 23 | 168139339 |
| 24 | 457225555 |
| 25 | 1244935251 |
| 26 | 3393754661 |
| 27 | 9261681937 |
| 28 | 25301337669 |
| 29 | 69184724389 |
| 30 | 189349490641 |