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 | 1 |
| 2 | 1 |
| 3 | 5 |
| 4 | 11 |
| 5 | 55 |
| 6 | 176 |
| 7 | 937 |
| 8 | 3781 |
| 9 | 21571 |
| 10 | 102455 |
| 11 | 624493 |
| 12 | 3356640 |
| 13 | 21752431 |
| 14 | 129055681 |
| 15 | 884773585 |
| 16 | 5696734715 |
| 17 | 41129090011 |
| 18 | 283908657880 |
| 19 | 2149818248341 |
| 20 | 15765656131765 |
| 21 | 124759995175751 |
| 22 | 965186517474191 |
| 23 | 7956847444317049 |
| 24 | 64577172850366176 |
| 25 | 553048437381116275 |