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 | 5 |
| 3 | 12 |
| 4 | 31 |
| 5 | 80 |
| 6 | 209 |
| 7 | 546 |
| 8 | 1429 |
| 9 | 3740 |
| 10 | 9791 |
| 11 | 25632 |
| 12 | 67105 |
| 13 | 175682 |
| 14 | 459941 |
| 15 | 1204140 |
| 16 | 3152479 |
| 17 | 8253296 |
| 18 | 21607409 |
| 19 | 56568930 |
| 20 | 148099381 |
| 21 | 387729212 |
| 22 | 1015088255 |
| 23 | 2657535552 |
| 24 | 6957518401 |
| 25 | 18215019650 |
| 26 | 47687540549 |
| 27 | 124847601996 |