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 | 25 |
| 1 | 1251 |
| 2 | 62575 |
| 3 | 3130001 |
| 4 | 156562625 |
| 5 | 7831261251 |
| 6 | 391719625175 |
| 7 | 19593812520001 |
| 8 | 980082345625225 |
| 9 | 49023711093781251 |
| 10 | 2452165637034687775 |
| 11 | 122657305562828170001 |
| 12 | 6135317443778443187825 |
| 13 | 306888529494484987561251 |