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 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 7 |
| 4 | 34 |
| 5 | 144 |
| 6 | 574 |
| 7 | 2226 |
| 8 | 8533 |
| 9 | 32587 |
| 10 | 124453 |
| 11 | 476145 |
| 12 | 1826175 |
| 13 | 7022379 |
| 14 | 27072487 |
| 15 | 104614863 |
| 16 | 405122290 |
| 17 | 1571859864 |
| 18 | 6109296442 |
| 19 | 23781666198 |
| 20 | 92704406320 |
| 21 | 361832294964 |
| 22 | 1413879679672 |
| 23 | 5530590849168 |
| 24 | 21654384302110 |
| 25 | 84859670743770 |
| 26 | 332818903663390 |