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 | 63 |
| 6 | 190 |
| 7 | 612 |
| 8 | 2056 |
| 9 | 7155 |
| 10 | 25482 |
| 11 | 92205 |
| 12 | 337594 |
| 13 | 1246863 |
| 14 | 4636390 |
| 15 | 17334801 |
| 16 | 65108062 |
| 17 | 245492244 |
| 18 | 928772650 |
| 19 | 3524337980 |
| 20 | 13409202676 |
| 21 | 51141124287 |
| 22 | 195470831356 |
| 23 | 748607855769 |
| 24 | 2872202028517 |
| 25 | 11038251159312 |