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) |
|---|---|
| 4 | 0 |
| 5 | 1 |
| 6 | 2 |
| 7 | 11 |
| 8 | 74 |
| 9 | 633 |
| 10 | 6134 |
| 11 | 64439 |
| 12 | 709302 |
| 13 | 8085725 |
| 14 | 94713809 |
| 15 | 1134914458 |
| 16 | 13865916560 |
| 17 | 172301697581 |
| 18 | 2173270387051 |