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 | 22 |
| 5 | 90 |
| 6 | 397 |
| 7 | 1859 |
| 8 | 9145 |
| 9 | 46882 |
| 10 | 248899 |
| 11 | 1361845 |
| 12 | 7650233 |
| 13 | 43990073 |
| 14 | 258287170 |
| 15 | 1545382674 |
| 16 | 9406108839 |
| 17 | 58155261970 |
| 18 | 364774287298 |
| 19 | 2318661708634 |
| 20 | 14921368078303 |
| 21 | 97132997631387 |
| 22 | 639118975577638 |
| 23 | 4247742637567555 |
| 24 | 28499086448886207 |