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 | 1 |
| 5 | 30 |
| 6 | 705 |
| 7 | 15960 |
| 8 | 370125 |
| 9 | 8998290 |
| 10 | 231416325 |
| 11 | 6314962500 |
| 12 | 182894567625 |
| 13 | 5615811951750 |
| 14 | 182497749258825 |
| 15 | 6264206330382000 |
| 16 | 226636350724909125 |
| 17 | 8624703350821808250 |
| 18 | 344535241891693978125 |
| 19 | 14419858385821910521500 |