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 | 4 |
| 2 | 25 |
| 3 | 400 |
| 4 | 2500 |
| 5 | 40000 |
| 6 | 250000 |
| 7 | 2805625 |
| 8 | 4000000 |
| 9 | 25000000 |
| 10 | 36300625 |
| 11 | 43890625 |
| 12 | 221265625 |
| 13 | 280562500 |
| 14 | 400000000 |
| 15 | 2500000000 |
| 16 | 3630062500 |
| 17 | 4389062500 |
| 18 | 22126562500 |
| 19 | 28056250000 |
| 20 | 40000000000 |
| 21 | 250000000000 |
| 22 | 363006250000 |
| 23 | 438906250000 |
| 24 | 2212656250000 |
| 25 | 2805625000000 |