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 | 9 |
| 4 | 80 |
| 5 | 900 |
| 6 | 12348 |
| 7 | 200704 |
| 8 | 3779136 |
| 9 | 81000000 |
| 10 | 1948717100 |
| 11 | 52027785216 |
| 12 | 1527047909712 |
| 13 | 48884036690944 |
| 14 | 1695352148437500 |
| 15 | 63331869759897600 |
| 16 | 2535571976423919872 |
| 17 | 108321063231221415936 |
| 18 | 4918685157679434648876 |