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 | 1 |
| 2 | 9 |
| 3 | 25 |
| 4 | 1225 |
| 5 | 3969 |
| 6 | 53361 |
| 7 | 184041 |
| 8 | 41409225 |
| 9 | 147744025 |
| 10 | 2133423721 |
| 11 | 7775536041 |
| 12 | 457028729521 |
| 13 | 1690195005625 |
| 14 | 25145962430625 |
| 15 | 93990019574025 |
| 16 | 90324408810638025 |
| 17 | 340357374376418025 |
| 18 | 5147380044581630625 |
| 19 | 19520119892056100625 |
| 20 | 1187604094232693162025 |