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 | 0 |
| 2 | -1 |
| 3 | 2 |
| 4 | 11 |
| 5 | 12 |
| 6 | 19 |
| 7 | 174 |
| 8 | 1073 |
| 9 | 6584 |
| 10 | 45871 |
| 11 | 337098 |
| 12 | 2563293 |
| 13 | 20346204 |
| 14 | 169904575 |
| 15 | 1501012310 |
| 16 | 14065496355 |
| 17 | 139601710224 |
| 18 | 1460544299739 |
| 19 | 16007830782402 |
| 20 | 182743810845223 |
| 21 | 2163753452707580 |
| 22 | 26506423427738891 |
| 23 | 335585442530912862 |
| 24 | 4389743577358599363 |