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 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 25 |
| 5 | 49 |
| 6 | 49 |
| 7 | 121 |
| 8 | 20449 |
| 9 | 20449 |
| 10 | 5909761 |
| 11 | 17631601 |
| 12 | 17631601 |
| 13 | 55190041 |
| 14 | 55190041 |
| 15 | 55190041 |
| 16 | 46414824481 |
| 17 | 154341336769 |
| 18 | 154341336769 |
| 19 | 427538329 |
| 20 | 585299972401 |
| 21 | 585299972401 |
| 22 | 983889253606081 |
| 23 | 3438962627443561 |
| 24 | 3438962627443561 |
| 25 | 7596668444022826249 |