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 | 6 |
| 3 | 15 |
| 4 | 44 |
| 5 | 105 |
| 6 | 258 |
| 7 | 595 |
| 8 | 1368 |
| 9 | 3069 |
| 10 | 6830 |
| 11 | 15015 |
| 12 | 32772 |
| 13 | 70993 |
| 14 | 152922 |
| 15 | 327675 |
| 16 | 699056 |
| 17 | 1485477 |
| 18 | 3145734 |
| 19 | 6640975 |
| 20 | 13981020 |
| 21 | 29360121 |
| 22 | 61516466 |
| 23 | 128625315 |
| 24 | 268435464 |
| 25 | 559240525 |
| 26 | 1163220318 |
| 27 | 2415919095 |
| 28 | 5010795188 |
| 29 | 10379504289 |
| 30 | 21474836490 |
| 31 | 44381328715 |