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 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 2 |
| 6 | 3161 |
| 7 | 147502 |
| 8 | 2251309 |
| 9 | 19028431 |
| 10 | 111126797 |
| 11 | 503008566 |
| 12 | 1888247929 |
| 13 | 6139119795 |
| 14 | 17805426945 |
| 15 | 47050056470 |
| 16 | 115056780421 |
| 17 | 263499318031 |
| 18 | 570427305781 |
| 19 | 1175960541134 |
| 20 | 2322552621393 |
| 21 | 4416363482851 |
| 22 | 8118552261033 |
| 23 | 14478163221342 |
| 24 | 25121835774173 |