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 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 25 |
| 5 | 49 |
| 6 | 441 |
| 7 | 1089 |
| 8 | 184041 |
| 9 | 511225 |
| 10 | 5909761 |
| 11 | 17631601 |
| 12 | 863948449 |
| 13 | 2704312009 |
| 14 | 34493775625 |
| 15 | 111759833025 |
| 16 | 93990019574025 |
| 17 | 312541206957225 |
| 18 | 4201942893536025 |
| 19 | 14258670483605625 |
| 20 | 780804795682244025 |