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 | 1 |
| 3 | 6 |
| 4 | 41 |
| 5 | 340 |
| 6 | 3361 |
| 7 | 38682 |
| 8 | 508241 |
| 9 | 7506504 |
| 10 | 123108961 |
| 11 | 2219822990 |
| 12 | 43648348985 |
| 13 | 929502984540 |
| 14 | 21311829302401 |
| 15 | 523455901397730 |
| 16 | 13712375005949345 |
| 17 | 381621247702458640 |
| 18 | 11244620308691664961 |
| 19 | 349715433597469496982 |
| 20 | 11448372539225223596105 |
| 21 | 393503844330372123056100 |
| 22 | 14169282835811140260616801 |