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 | 64 |
| 5 | 1900 |
| 6 | 5184 |
| 7 | 695310 |
| 8 | 15089664 |
| 9 | 346348629 |
| 10 | 8189440000 |
| 11 | 170553548176 |
| 12 | 4519967588352 |
| 13 | 202522159449675 |
| 14 | 8500218417954816 |
| 15 | 265594041953296875 |
| 16 | 3543051899458551808 |
| 17 | 454740628232312103872 |
| 18 | 5853583711033675481088 |
| 19 | 1445271811400044958489895 |
| 20 | 91546885417441689600000000 |