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 | 0 |
| 3 | 1 |
| 4 | 2 |
| 5 | 10 |
| 6 | 28 |
| 7 | 125 |
| 8 | 497 |
| 9 | 2345 |
| 10 | 11497 |
| 11 | 61688 |
| 12 | 350543 |
| 13 | 2126495 |
| 14 | 13631966 |
| 15 | 92197099 |
| 16 | 654982126 |
| 17 | 4874404106 |
| 18 | 37892942311 |
| 19 | 306986431845 |
| 20 | 2586206074833 |
| 21 | 22612848380851 |
| 22 | 204850698287662 |
| 23 | 1919652428481928 |
| 24 | 18581619383614327 |
| 25 | 185543613289199731 |
| 26 | 1908894095258021121 |