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 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 3 |
| 5 | 11 |
| 6 | 38 |
| 7 | 163 |
| 8 | 884 |
| 9 | 5621 |
| 10 | 41971 |
| 11 | 355823 |
| 12 | 3360794 |
| 13 | 34734530 |
| 14 | 388337048 |
| 15 | 4656198401 |
| 16 | 59501173436 |
| 17 | 806454404157 |
| 18 | 11547541311414 |
| 19 | 174108338688997 |
| 20 | 2756331807471302 |
| 21 | 45702073130849321 |
| 22 | 791884792034547926 |
| 23 | 14309888992592592578 |
| 24 | 269194860146567854175 |