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 | 6 |
| 2 | 75 |
| 3 | 708 |
| 4 | 5991 |
| 5 | 47868 |
| 6 | 369315 |
| 7 | 2783448 |
| 8 | 20631126 |
| 9 | 151026498 |
| 10 | 1094965524 |
| 11 | 7878119760 |
| 12 | 56330252412 |
| 13 | 400703095284 |
| 14 | 2838060684483 |
| 15 | 20027058300144 |
| 16 | 140874026880204 |
| 17 | 988194254587242 |
| 18 | 6915098239841331 |
| 19 | 48285969880645908 |
| 20 | 336521149274459979 |