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) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 1 |
| 7 | 3 |
| 8 | 36 |
| 9 | 296 |
| 10 | 2303 |
| 11 | 16317 |
| 12 | 110462 |
| 13 | 717024 |
| 14 | 4532105 |
| 15 | 28046285 |
| 16 | 170938814 |
| 17 | 1029749994 |
| 18 | 6149327905 |
| 19 | 36477979041 |
| 20 | 215304158916 |
| 21 | 1265984738264 |
| 22 | 7422971231829 |
| 23 | 43433472086235 |
| 24 | 253759842223290 |