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 | 4 |
| 2 | 49 |
| 3 | 200 |
| 4 | 2449 |
| 5 | 9996 |
| 6 | 122401 |
| 7 | 499600 |
| 8 | 6117601 |
| 9 | 24970004 |
| 10 | 305757649 |
| 11 | 1248000600 |
| 12 | 15281764849 |
| 13 | 62375059996 |
| 14 | 763782484801 |
| 15 | 3117504999200 |
| 16 | 38173842475201 |
| 17 | 155812874900004 |
| 18 | 1907928341275249 |
| 19 | 7787526240001000 |
| 20 | 95358243221287249 |
| 21 | 389220499125149996 |