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 | 2 |
| 2 | 4 |
| 3 | 9 |
| 4 | 23 |
| 5 | 66 |
| 6 | 210 |
| 7 | 733 |
| 8 | 2781 |
| 9 | 11378 |
| 10 | 49864 |
| 11 | 232769 |
| 12 | 1151915 |
| 13 | 6018786 |
| 14 | 33087206 |
| 15 | 190780213 |
| 16 | 1150653921 |
| 17 | 7241710930 |
| 18 | 47454745804 |
| 19 | 323154696185 |
| 20 | 2282779990495 |
| 21 | 16700904488706 |
| 22 | 126356632390298 |
| 23 | 987303454928973 |
| 24 | 7957133905608837 |
| 25 | 66071772829247410 |