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 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 9 |
| 6 | 21 |
| 7 | 44 |
| 8 | 103 |
| 9 | 232 |
| 10 | 571 |
| 11 | 1368 |
| 12 | 3441 |
| 13 | 8653 |
| 14 | 22263 |
| 15 | 57518 |
| 16 | 150733 |
| 17 | 396937 |
| 18 | 1054540 |
| 19 | 2815453 |
| 20 | 7562159 |
| 21 | 20399714 |
| 22 | 55280532 |
| 23 | 150356806 |
| 24 | 410432671 |
| 25 | 1123902587 |
| 26 | 3086827578 |
| 27 | 8500975970 |
| 28 | 23470712241 |
| 29 | 64952794778 |
| 30 | 180144093389 |