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 | 1 |
| 3 | 4 |
| 4 | 25 |
| 5 | 121 |
| 6 | 729 |
| 7 | 5041 |
| 8 | 40401 |
| 9 | 362404 |
| 10 | 3629025 |
| 11 | 39917124 |
| 12 | 478996996 |
| 13 | 6226945921 |
| 14 | 87178467600 |
| 15 | 1307674583296 |
| 16 | 20922793332736 |
| 17 | 355687416544329 |
| 18 | 6402373660047556 |
| 19 | 121645100663836929 |
| 20 | 2432902009335560361 |
| 21 | 51090942169052381124 |
| 22 | 1124000727752683686724 |