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 | 1 |
| 3 | 1 |
| 4 | 2 |
| 5 | 5 |
| 6 | 13 |
| 7 | 27 |
| 8 | 74 |
| 9 | 198 |
| 10 | 508 |
| 11 | 1371 |
| 12 | 3809 |
| 13 | 10477 |
| 14 | 29116 |
| 15 | 82419 |
| 16 | 233748 |
| 17 | 666201 |
| 18 | 1914668 |
| 19 | 5528622 |
| 20 | 16019330 |
| 21 | 46642245 |
| 22 | 136326126 |
| 23 | 399652720 |
| 24 | 1175422931 |
| 25 | 3467251920 |
| 26 | 10258152021 |