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 | 1 |
| 2 | 0 |
| 3 | 3 |
| 4 | 3 |
| 5 | 13 |
| 6 | 26 |
| 7 | 77 |
| 8 | 192 |
| 9 | 529 |
| 10 | 1412 |
| 11 | 3873 |
| 12 | 10603 |
| 13 | 29315 |
| 14 | 81318 |
| 15 | 226763 |
| 16 | 634627 |
| 17 | 1782637 |
| 18 | 5022840 |
| 19 | 14193457 |
| 20 | 40211105 |
| 21 | 114191159 |
| 22 | 324981030 |
| 23 | 926720807 |
| 24 | 2647513282 |
| 25 | 7576475383 |
| 26 | 21716189676 |
| 27 | 62336237007 |
| 28 | 179182653117 |
| 29 | 515717424109 |
| 30 | 1486119467026 |