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 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 21 |
| 5 | 82 |
| 6 | 343 |
| 7 | 1509 |
| 8 | 6893 |
| 9 | 32419 |
| 10 | 156058 |
| 11 | 765578 |
| 12 | 3815062 |
| 13 | 19263736 |
| 14 | 98368919 |
| 15 | 507197436 |
| 16 | 2637242188 |
| 17 | 13814247530 |
| 18 | 72834238423 |
| 19 | 386244387688 |
| 20 | 2058933104170 |
| 21 | 11026807340592 |
| 22 | 59304897232442 |
| 23 | 320181600386661 |
| 24 | 1734685419170666 |
| 25 | 9428340999504441 |