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 | 5625 |
| 2 | 50625 |
| 3 | 275625 |
| 4 | 1500625 |
| 5 | 6002500 |
| 6 | 24010000 |
| 7 | 77792400 |
| 8 | 252047376 |
| 9 | 700131600 |
| 10 | 1944810000 |
| 11 | 4802490000 |
| 12 | 11859210000 |
| 13 | 26683222500 |
| 14 | 60037250625 |
| 15 | 125262905625 |
| 16 | 261351000625 |
| 17 | 512247961225 |
| 18 | 1004006004001 |
| 19 | 1866953313225 |
| 20 | 3471607400625 |